Metal complexes comprising diazabenzimidazolocarbene ligands and the use thereof in oleds

ABSTRACT

The present invention relates to metal-carbene complexes comprising a central atom selected from iridium and platinum, and diazabenzimidazolocarbene ligands, to organic light diodes which comprise such complexes, to light-emitting layers comprising at least one such metal-carbene complex, to a device selected from the group comprising illuminating elements, stationary visual display units and mobile visual display units comprising such an OLED and to the use of such a metal-carbene complex in OLEDs, for example as emitter, matrix material, charge transport material and/or charge or exciton blocker.

The present invention relates to metal-carbene complexes comprising acentral atom selected from iridium and platinum, anddiazabenzimidazolocarbene ligands, to OLEDs (Organic Light-EmittingDiodes) which comprise such complexes, to light-emitting layerscomprising at least one such metal-carbene complex, to a device selectedfrom the group consisting of illuminating elements, stationary visualdisplay units and mobile visual display units comprising such an OLED,to the use of such a metal-carbene complex in OLEDs, for example asemitter, matrix material, charge transport material and/or charge orexciton blocker.

organic light-emitting diodes (OLEDs) exploit the propensity ofmaterials to emit light when they are excited by electrical current.OLEDs are of particular interest as an alternative to cathode ray tubesand liquid-crystal displays for production of flat visual display units.Owing to the very compact design and the intrinsically low powerconsumption, devices comprising OLEDs are suitable especially for mobileapplications, for example for applications in cellphones, laptops, etc.In addition, white OLEDs give great advantages over the illuminationtechnologies known to date, especially a particularly high efficiency.

The prior art proposes numerous materials which emit light on excitationby electrical current.

WO 2005/019373 discloses transition metal complexes with carbene ligandsas emitters for organic light-emitting diodes (OLEDs). The ligands ofthese transition metal complexes are preferably attached via ametal-carbene bond and via a bond between the metal atom and an aromaticradical. Numerous heterocycles attached to the metal atom via a carbenebond are disclosed, but no complexes which havediazabenzimidazolocarbene ligands are disclosed.

WO 2006/056418 A2 discloses the use of transition metal-carbenecomplexes in organic light-emitting diodes. In the correspondingtransition metal complexes, a metal atom is bonded to the ligands via atleast one metal-carbene bond and via a bond between the metal atom andan aromatic radical. The metal-carbene bond is preferably via animidazole ring, to which, according to the document cited, aromaticcycles may also be fused. However, no complexes which havediazabenzimidazolocarbene ligands are disclosed.

WO 2007/088093 A1 and WO 2007/185981 A1 disclose transition metalcomplexes comprising ligands attached via metal-carbene bonds. Preferredcarbene ligands mentioned are imidazole ligands. These may also havefused aromatic six-membered rings, where 1 to 4 of the carbon atomspresent in the aromatic six-membered ring may be replaced by nitrogen.The documents cited do not disclose the positions of the nitrogens inthe aromatic six-membered ring.

WO 2007/115970 A1 likewise discloses transition metal-carbene complexes,preference being given to imidazole units as the carbene ligand. Anaromatic six-membered ring may likewise be fused to this imidazole unit,wherein 1 to 4 carbon atoms may be replaced by nitrogen atoms. Nor doesthis document comprise any disclosure as to the position of the nitrogenatoms.

Even though compounds which exhibit electroluminescence in the visibleregion, more particularly in the blue region, of the electromagneticspectrum, are already known, the provision of compounds which exhibitlong diode lifetimes is desirable. In the context of the presentinvention, electroluminescence is understood to mean bothelectrofluorescence and electrophosphorescence.

It is therefore an object of the present invention to providealternative iridium and platinum complexes which are suitable forelectroluminescence in the visible region, more particularly in the blueregion, of the electromagnetic spectrum, which enables the production offull-color displays and white OLEDs. It is a further object of thepresent invention to provide corresponding complexes which can be usedas a mixture with a host compound (matrix material) as a light-emittinglayer in OLEDs. It is a further object of the present invention toprovide corresponding complexes which have a high quantum yield and ahigh stability in diodes. The complexes should be usable as emitter,matrix material, charge transport material, especially hole transportmaterial or charge blocker in OLEDs.

These objects are achieved in accordance with the invention bymetal-carbene complexes of the general formula (I)

where M, n, Y, A², A³, A⁴, A⁵, R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰,K, L, m and o are each defined as follows:

-   M is Ir or Pt,-   n is an integer selected from 1, 2 and 3,-   Y is NR¹, O, S or C(R¹⁰)₂,-   A², A³, A⁴, A⁵ are each independently N or C, where 2 A=nitrogen    atoms and at least one carbon atom is present between two nitrogen    atoms in the ring,-   R¹ is a linear or branched alkyl radical optionally interrupted by    at least one heteroatom, optionally bearing at least one functional    group and having 1 to 20 carbon atoms, cycloalkyl radical optionally    interrupted by at least one heteroatom, optionally bearing at least    one functional group and having 3 to 20 carbon atoms, substituted or    unsubstituted aryl radical optionally interrupted by at least one    heteroatom, optionally bearing at least one functional group and    having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl    radical optionally interrupted by at least one heteroatom,    optionally bearing at least one functional group and having a total    of 5 to 18 carbon atoms and/or heteroatoms,-   R², R³, R⁴, R⁵ are each, if A², A³, A⁴ and/or A⁵ is N, a free    electron pair, or, if A², A³, A⁴ and/or A⁵ is C, each independently    hydrogen, linear or branched alkyl radical optionally interrupted by    at least one heteroatom, optionally bearing at least one functional    group and having 1 to 20 carbon atoms, cycloalkyl radical optionally    interrupted by at least one heteroatom, optionally bearing at least    one functional group and having 3 to 20 carbon atoms, substituted or    unsubstituted aryl radical optionally interrupted by at least one    heteroatom, optionally bearing at least one functional group and    having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl    radical optionally interrupted by at least one heteroatom,    optionally bearing at least one functional group and having a total    of 5 to 18 carbon atoms and/or heteroatoms, group with donor or    acceptor action,    or    R³ and R⁴ together with A³ and A⁴ form an optionally substituted,    unsaturated ring optionally interrupted by at least one further    heteroatom and having a total of 5 to 18 carbon atoms and/or    heteroatoms,-   R⁶, R⁷, R⁸, R⁹ are each independently hydrogen, linear or branched    alkyl radical optionally interrupted by at least one heteroatom,    optionally bearing at least one functional group and having 1 to 20    carbon atoms, cycloalkyl radical optionally interrupted by at least    one heteroatom, optionally bearing at least one functional group and    having 3 to 20 carbon atoms, cycloheteroalkyl radical optionally    interrupted by at least one heteroatom, optionally bearing at least    one functional group and having 3 to 20 carbon atoms, substituted or    unsubstituted aryl radical optionally interrupted by at least one    heteroatom, optionally bearing at least one functional group and    having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl    radical optionally interrupted by at least one heteroatom,    optionally bearing at least one functional group and having a total    of 5 to 18 carbon atoms and/or heteroatoms, group with donor or    acceptor action,    or    R⁶ and R⁷, R⁷ and R⁸ or R⁸ and R⁹, together with the carbon atoms to    which they are bonded, form an unsaturated or aromatic, optionally    substituted ring optionally interrupted by at least one heteroatom    and having a total of 5 to 18 carbon atoms and/or heteroatoms,    and/or    if A⁵ is C, R⁵ and R⁶ together form a saturated or unsaturated,    linear or branched bridge optionally comprising heteroatoms, an    aromatic unit, heteroaromatic unit and/or functional groups and    having a total of 1 to 30 carbon atoms and/or heteroatoms, to which    is optionally fused a substituted or unsubstituted, five- to    eight-membered ring comprising carbon atoms and/or heteroatoms,-   R¹⁰ is independently a linear or branched alkyl radical optionally    interrupted by at least one heteroatom, optionally bearing at least    one functional group and having 1 to 20 carbon atoms, cycloalkyl    radical optionally interrupted by at least one heteroatom,    optionally bearing at least one functional group and having 3 to 20    carbon atoms, substituted or unsubstituted aryl radical optionally    interrupted by at least one heteroatom, optionally bearing at least    one functional group and having 6 to 30 carbon atoms, substituted or    unsubstituted heteroaryl radical optionally interrupted by at least    one heteroatom, optionally bearing at least one functional group and    having a total of 5 to 18 carbon atoms and/or heteroatoms,-   K is an uncharged mono- or bidentate ligand,-   L is a mono- or dianionic ligand, preferably monoanionic ligand,    which may be mono- or bidentate,-   m is 0, 1 or 2, where, when m is 2, the K ligands may be the same or    different,-   o is 0, 1 or 2, where, when o is 2, the L ligands may be the same or    different.

When m and o are each 0, in accordance with the invention, homolepticmetal-carbene complexes of the general formula (I) are present. When atleast one of m and o is 1 or 2, in accordance with the invention,heteroleptic metal-carbene complexes of the general formula (I) arepresent.

In the context of the present invention, the terms aryl radical, unit orgroup, heteroaryl radical, unit or group, alkyl radical, unit or groupand cycloalkyl radical, unit or group are each defined as follows—unlessstated otherwise:

An aryl radical, unit or group is understood to mean a radical with abase skeleton of 6 to 30 carbon atoms, preferably 6 to 18 carbon atoms,which is formed from an aromatic ring or a plurality of fused aromaticrings. Suitable base skeletons are, for example, phenyl, naphthyl,anthracenyl or phenanthrenyl. This base skeleton may be unsubstituted,which means that all carbon atoms which are substitutable bear hydrogenatoms, or may be substituted at one or more, or all, substitutablepositions of the base skeleton.

Suitable substituents are, for example, alkyl radicals, preferably alkylradicals having 1 to 8 carbon atoms, more preferably methyl, ethyl,i-propyl, t-butyl, neopentyl, aryl radicals, preferably C₆-arylradicals, which may in turn be substituted or unsubstituted, heteroarylradicals, preferably heteroaryl radicals which comprise at least onenitrogen atom, more preferably pyridyl radicals, alkenyl radicals,preferably alkenyl radicals which bear one double bond, more preferablyalkenyl radicals with one double bond and 1 to 8 carbon atoms, or groupswith donor or acceptor action. Groups with donor action are understoodto mean groups which have a +I and/or +M effect, and groups withacceptor action are understood to mean groups which have a −I and/or −Meffect. Suitable groups with donor or acceptor action are halogenradicals, preferably F, Cl, Br, more preferably F, alkyl radicals, silylradicals, siloxy radicals, alkoxy radicals, aryloxy radicals, carbonylradicals, ester radicals, amine radicals, amide radicals, CH₂F groups,CHF₂ groups, CF₃ groups, CN groups, thio groups or SCN groups. The arylradicals most preferably bear substituents selected from the groupconsisting of methyl, ethyl, iso-propyl, n-propyl, n-butyl, iso-butyl,tert-butyl, neopentyl, CF₃, aryloxy, amine, thio groups and alkoxy, orthe aryl radicals are unsubstituted. The aryl radical or the aryl groupis preferably a C₆-aryl radical optionally substituted by at least oneof the aforementioned substituents. The C₆-aryl radical more preferablyhas none, one, two or three of the aforementioned substituents.

A heteroaryl radical or a heteroaryl unit or group is understood to meanradicals having 5 to 30 carbon atoms and/or heteroatoms, which differfrom the aforementioned aryl radicals in that at least one carbon atomin the base skeleton of the aryl radicals is replaced by a heteroatom.Preferred heteroatoms are N, O and S. Most preferably, one or two carbonatoms of the base skeleton of the aryl radicals are replaced byheteroatoms. The base skeleton is especially preferably selected fromelectron-poor systems such as pyridyl, pyrimidyl, pyrazyl and triazolyl,and five-membered heteroaromatics such as pyrrole, furan, thiophene,imidazole, pyrazole, triazole, oxazole and thiazole. The base skeletonmay be substituted at one, more than one or all substitutable positionsof the base skeleton. Suitable substituents are the same as have alreadybeen specified above for the aryl groups.

An alkyl radical or an alkyl group is understood to mean a radicalhaving 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, morepreferably 1 to 8 carbon atoms. This alkyl radical may be branched orunbranched and may optionally be interrupted by one or more heteroatoms,preferably N, O or S. In addition, this alkyl radical may be substitutedby one or more of the substituents already specified for the arylgroups. It is likewise possible that the alkyl radical bears one or morearyl groups. All of the aryl groups listed above are suitable.Particular preference is given to the alkyl radicals selected from thegroup consisting of methyl, ethyl, i-propyl, n-propyl, i-butyl, n-butyl,t-butyl, sec-butyl, i-pentyl, n-pentyl, sec-pentyl, neopentyl, n-hexyl,i-hexyl and sec-hexyl. Very particular preference is given to methyl,i-propyl, tert-butyl and neopentyl.

A cycloalkyl radical or a cycloalkyl group is understood to mean acyclic radical having 3 to 20 carbon atoms, preferably 3 to 10 carbonatoms, more preferably 3 to 8 carbon atoms. This cycloalkyl radical mayoptionally be interrupted by one or more heteroatoms, preferably N, O orS. In addition, this cycloalkyl radical may be unsubstituted orsubstituted, i.e. may be substituted by one or more of the substituentsalready specified for the aryl groups. It is likewise possible that thecycloalkyl radical bears one or more aryl groups. All aryl groups listedabove are suitable.

The statements made for the aryl, heteroaryl, alkyl and cycloalkylradicals apply, in accordance with the invention, independently to theradicals mentioned in the present application, where R², R³, R⁴ and R⁵,in the case that A², A³, A⁴ and/or A⁵ is N, are a free electron pair,which means that no substituent selected from the above-mentioned groupis present on these ring nitrogen atoms. In the case that A², A³, A⁴and/or A⁵ is C, R², R³, R⁴ and R⁵ are each independently hydrogen and/orthe substituents specified.

K in the general formula (I) is an uncharged mono- or bidentate ligand,and L in the general formula (I) is a mono- or dianionic ligand,preferably a monoanionic ligand which may be mono- or bidentate.

A bidentate ligand is understood to mean a ligand coordinated at twosites to the transition metal atom M. A monodentate ligand is understoodto mean a ligand coordinated at one site on the ligand to the transitionmetal atom M.

Suitable mono- or dianionic ligands L, preferably monoanionic ligands Lwhich may be mono- or bidentate, are the ligands typically used as mono-or bidentate mono- or dianionic ligands.

Suitable monoanionic monodentate ligands are, for example, halides,especially or and Br⁻, pseudohalides, especially CN⁻, cyclopentadienyl(Cp⁻), hydride, alkyl radicals joined to the transition metal M via asigma bond, for example CH₃, alkylaryl radicals joined to the transitionmetal M via a sigma bond, for example benzyl.

Suitable monoanionic bidentate ligands are, for example, acetylacetonateand derivatives thereof, picolinate, Schiff bases, amino acids,arylpyridines, e.g. phenylpyridine, and the further bidentatemonoanionic ligands specified in WO 02/15645, carbene ligands asspecified in WO2006056418 and in EP1658343, arylazoles, e.g.2-arylimidazoles, preference being given to 2-arylimidazoles and carbeneligands.

Suitable dianionic bidentate ligands are, for example, dialkoxides,dicarbonates, dicarboxylates, diamides, diimides, dithiolates,biscyclopentadienyls, bisphosphonates, bissulfonates and3-phenylpyrazole.

Suitable uncharged mono- or bidentate ligands K are preferably selectedfrom the group consisting of phosphines, both mono- and bisphosphines;phosphonates, both mono- and bisphosphonates, and derivatives thereof,arsenates, both mono- and bisarsenates, and derivatives thereof;phosphites, both mono- and bisphosphites; CO; pyridines, both mono- andbispyridines; nitriles, dinitriles, allyl, diimines, nonconjugateddienes and conjugated dienes which form a π complex with M¹.Particularly preferred uncharged mono- or bidentate ligands K areselected from the group consisting of phosphines, both mono- andbisphosphines, preferably trialkyl-, triaryl- or alkylarylphosphines,more preferably PAr₃ where Ar is a substituted or unsubstituted arylradical and the three aryl radicals in PAr₃ may be the same ordifferent, more preferably PPh₃, PEt₃, PnBu₃, PEt₂Ph, PMe₂Ph, PnBu₂Ph;phosphonates and derivatives thereof, arsenates and derivatives thereof,phosphites, CO; pyridines, both mono- and bispyridines, where thepyridines may be substituted by alkyl or aryl groups; nitriles anddienes which form a it complex with M¹, preferablyη⁴-diphenyl-1,3-butadiene, η⁴-1,3-pentadiene,η⁴-1-phenyl-1,3-pentadiene, η⁴-1,4-dibenzyl-1,3-butadiene,η⁴-2,4-hexadiene, η⁴-3-methyl-1,3-pentadiene,η⁴-1,4-ditolyl-1,3-butadiene, η⁴-1,4-bis(trimethylsilyl)-1,3-butadieneand η²- or η⁴-cyclooctadiene (each 1,3 and each 1,5), more preferably1,4-diphenyl-1,3-butadiene, 1-phenyl-1,3-pentadiene, 2,4-hexadiene,butadiene, η²-cyclooctene, η⁴-1,3-cyclooctadiene andη⁴-1,5-cyclooctadiene. Very particularly preferred uncharged monodentateligands are selected from the group consisting of PPh₃, P(OPh)₃, AsPh₃,CO, pyridine, nitriles and derivatives thereof. Suitable uncharged mono-or bidentate ligands are preferably 1,4-diphenyl-1,3-butadiene,1-phenyl-1,3-pentadiene, 2,4-hexadiene, η⁴-cyclooctadiene andη²-cyclooctadiene (each 1,3 and each 1,5).

The number o of monoanionic ligands L in the aforementioned case is 0,1, 2. When o>1, the L ligands may be the same or different, and arepreferably the same.

The number m of uncharged ligands K depends on whether the coordinationnumber 6 of the Ir(III) or 4 of the Pt(II) has already been attainedwith the aid of the carbene ligands and of the ligands L. When—in thecase that Ir(III) is used—n is three and three monoanionic bidentatecarbene ligands are used, m in the aforementioned case is 0. When—in thecase that Pt(II) is used—n is two and two monoanionic bidentate carbeneligands are used, m in this case is likewise 0.

In a further preferred embodiment, the present invention relates to aninventive metal-carbene complex where L in the general formula (I) is acarbene ligand of the general formula (II)

where

-   A⁶, A⁷ are each independently C or N-   R¹¹ is a linear or branched alkyl radical optionally interrupted by    at least one heteroatom, optionally bearing at least one functional    group and having 1 to 20 carbon atoms, cycloalkyl radical optionally    interrupted by at least one heteroatom, optionally bearing at least    one functional group and having 3 to 20 carbon atoms,    cycloheteroalkyl radical optionally interrupted by at least one    heteroatom, optionally bearing at least one functional group and    having 3 to 20 carbon atoms, substituted or unsubstituted aryl    radical optionally interrupted by at least one heteroatom,    optionally bearing at least one functional group and having 6 to 30    carbon atoms, substituted or unsubstituted heteroaryl radical    optionally interrupted by at least one heteroatom, optionally    bearing at least one functional group and having a total of 5 to 18    carbon atoms and/or heteroatoms,-   R¹², R¹³ are each independently, when A is N, a free electron pair,    or, when A is C, hydrogen, linear or branched alkyl radical    optionally interrupted by at least one heteroatom, optionally    bearing at least one functional group and having 1 to 20 carbon    atoms, cycloalkyl radical optionally interrupted by at least one    heteroatom, optionally bearing at least one functional group and    having 3 to 20 carbon atoms, cycloheteroalkyl radical optionally    interrupted by at least one heteroatom, optionally bearing at least    one functional group and having 3 to 20 carbon atoms, substituted or    unsubstituted aryl radical optionally interrupted by at least one    heteroatom, optionally bearing at least one functional group and    having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl    radical optionally interrupted by at least one heteroatom,    optionally bearing at least one functional group and having a total    of 5 to 18 carbon atoms and/or heteroatoms, group with donor or    acceptor action,-   R¹⁴, R¹⁵, R¹⁶, R¹⁷ are each independently hydrogen, linear or    branched alkyl radical optionally interrupted by at least one    heteroatom, optionally bearing at least one functional group and    having 1 to 20 carbon atoms, cycloalkyl radical optionally    interrupted by at least one heteroatom, optionally bearing at least    one functional group and having 3 to 20 carbon atoms,    cycloheteroalkyl radical optionally interrupted by at least one    heteroatom, optionally bearing at least one functional group and    having 3 to 20 carbon atoms, substituted or unsubstituted aryl    radical optionally interrupted by at least one heteroatom,    optionally bearing at least one functional group and having 6 to 30    carbon atoms, substituted or unsubstituted heteroaryl radical    optionally interrupted by at least one heteroatom, optionally    bearing at least one functional group and having a total of 5 to 18    carbon atoms and/or heteroatoms, group with donor or acceptor    action,    or    R¹² and R¹³, R¹⁴ and R¹⁵, R¹⁵ and R¹⁶ or R¹⁶ and R¹⁷ form, together    with A or the carbon atoms to which they are bonded, an unsaturated    or aromatic, optionally substituted ring optionally interrupted by    at least one heteroatom and having a total of 5 to 18 carbon atoms    and/or heteroatoms,    and/or    if A⁶ is C, R¹³ and R¹⁴ together form a saturated or unsaturated,    linear or branched bridge optionally comprising heteroatoms,    aromatic units, heteroaromatic units and/or functional groups and    having a total of 1 to 30 carbon atoms and/or heteroatoms, to which    is optionally fused a substituted or unsubstituted, five- to    eight-membered ring comprising carbon atoms and/or heteroatoms.

In a further preferred embodiment, the present invention relates to aninventive metal-carbene complex where L in the general formula (I) is a

heterocyclic noncarbene ligand of the general formula (III)

in which the symbols in the ligand of the general formula IV are eachdefined as follows:

-   D are each independently CR¹⁸ or N, preferably CR¹⁸;-   W is C, N, preferably C;-   E are each independently CR¹⁹, N, NR²⁰, preferably CR¹⁹ or N;-   G is CR²¹, N, NR²², S, O, preferably NR²¹-   R¹⁸, R¹⁹ R²¹ are each independently hydrogen, linear or branched    alkyl radical optionally interrupted by at least one heteroatom,    optionally bearing at least one functional group and having 1 to 20    carbon atoms, cycloalkyl radical optionally interrupted by at least    one heteroatom, optionally bearing at least one functional group and    having 3 to 20 carbon atoms, cycloheteroalkyl radical optionally    interrupted by at least one heteroatom, optionally bearing at least    one functional group and having 3 to 20 carbon atoms, substituted or    unsubstituted aryl radical optionally interrupted by at least one    heteroatom, optionally bearing at least one functional group and    having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl    radical optionally interrupted by at least one heteroatom,    optionally bearing at least one functional group and having a total    of 5 to 18 carbon atoms and/or heteroatoms, group with donor or    acceptor action,    or in each case 2 R¹⁸, R¹⁹ and R²¹ radicals, together with the    carbon atoms to which they are bonded, form a saturated, unsaturated    or aromatic, optionally substituted ring optionally interrupted by    at least one heteroatom and having a total of 5 to 18 carbon atoms    and/or heteroatoms,-   R²⁰, R²² are each independently a linear or branched alkyl radical    optionally interrupted by at least one heteroatom, optionally    bearing at least one functional group and having 1 to 20 carbon    atoms, cycloalkyl radical optionally interrupted by at least one    heteroatom, optionally bearing at least one functional group and    having 3 to 20 carbon atoms, cycloheteroalkyl radical optionally    interrupted by at least one heteroatom, optionally bearing at least    one functional group and having 3 to 20 carbon atoms, substituted or    unsubstituted aryl radical optionally interrupted by at least one    heteroatom, optionally bearing at least one functional group and    having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl    radical optionally interrupted by at least one heteroatom,    optionally bearing at least one functional group and having a total    of 5 to 18 carbon atoms and/or heteroatoms, group with donor or    acceptor action; preferably o,o′-dialkylated aryl radical,    where the solid curved line is an optional bridge between one of the    D groups and the G group; where the bridge may be defined as    follows:    alkylene, arylene, heteroarylene, alkynylene, alkenylene, NR²³, O,    S, SiR²⁴R²⁵ and (CR²⁶R²⁷)_(d), where one or more nonadjacent    (CR²⁶R²⁷) groups may be replaced by NR²³, O, S, SiR²⁴R²⁵, where    d is 2 to 10;    and    23,-   R²⁴, R²⁵, R²⁶, R²⁷ are each H, alkyl, aryl, heteroaryl, alkenyl,    alkynyl.

For the inventive embodiment wherein in each case 2 R¹⁸, R¹⁹ and R²¹radicals, together with the carbon atoms to which they are bonded, forma saturated, unsaturated or aromatic, optionally substituted ringoptionally interrupted by at least one heteroatom and having a total of5 to 18 carbon atoms and/or heteroatoms, for example, two R¹⁸ radicals,two R¹⁹ radicals or one R¹⁹ radical and one R²¹ radical form acorresponding ring.

Ligands L which are very particularly preferred in accordance with theinvention are depicted below:

Further preferred ligands L:

In a preferred embodiment, M, n, Y, A², A³, A⁴, A⁵, R¹, R², R³, R⁴, R⁵,R⁶, R⁷, R⁸, R⁹, R¹⁰, K, L, n and o in the general formula (I) are eachdefined as follows:

According to the invention, M is Ir or Pt, preferably Ir. Ir is presentin the inventive complexes in the +3 oxidation state. Pt is present inthe inventive complexes in the +2 oxidation state.

n is generally 1, 2 or 3. If M is Ir, n is preferably 3. If M is Pt, nis preferably 1.

According to the invention, Y is NR¹, O, S or C(R²⁵)₂, preferably NR¹.

According to the invention, A², A³, A⁴ and A⁵ are each independently Cor N, where 2 A=nitrogen atoms and at least one carbon atom is presentbetween two nitrogen atoms in the ring. In general, one or two carbonatoms are present between two nitrogen atoms.

Preference is given in accordance with the invention to the followingembodiments:

-   1. A² and A⁵ are each N, and A³ and A⁴ are each C, i.e. the    inventive metal-carbene complexes comprise, in this preferred    embodiment, at least one pyrazinoimidazole unit which is attached    via a metal-carbene bond and is of the general formula (Ia)

-   2. A² and A⁴ are each N, A³ and A⁵ are each C, i.e. the inventive    metal-carbene complexes comprise, in this preferred embodiment, at    least one pyrimidinoimidazole unit which is attached via a    metal-carbene bond and is of the general formula (Ib)

-   3. A³ and A⁵ are each N, A² and A⁴ are each C, i.e. the inventive    metal-carbene complexes comprise, in this preferred embodiment, at    least one pyrimidinoimidazole unit which is attached via a    metal-carbene bond and is of the general formula (Ic)

In the general formulae (Ia), (Ib) and (Ic), the same definitions applyas in the general formula (I).

In the preferred case that Y is NR¹, R¹ in a preferred embodiment is alinear or branched alkyl radical having 1 to 6 carbon atoms, substitutedor unsubstituted aryl radical having 6 to 30 carbon atoms, substitutedor unsubstituted heteroaryl radical having a total of 5 to 18 carbonatoms and/or heteroatoms.

R¹ is more preferably linear or branched alkyl radical having 1 to 6carbon atoms, substituted or unsubstituted phenyl radical, substitutedor unsubstituted heteroaryl radical having a total of 5 or 6 carbonatoms and/or heteroatoms.

R¹ is most preferably selected from phenyl, tolyl, mesityl, thiophenyl,furanyl, pyridyl, methyl, isopropyl and neopentyl.

The present invention therefore relates especially to an inventivemetal-carbene complex in which Y is NR¹ where R¹ is selected from thegroup consisting of phenyl, tolyl, mesityl, thiophenyl, furanyl,pyridyl, methyl, isopropyl and neopentyl.

In a preferred embodiment, R², R³, R⁴, R⁵ are each independentlyhydrogen, a linear or branched alkyl radical having 1 to 20 carbonatoms, a substituted or unsubstituted aryl radical having 6 to 30 carbonatoms, a substituted or unsubstituted heteroaryl radical having 5 to 18carbon atoms and/or heteroatoms or silyl radical.

In a preferred embodiment, R², R³, R⁴, R⁵ are each, if A², A³, A⁴ and/orA⁵ is N, a free electron pair, or, if A², A³, A⁴ and/or A⁵ is C, eachindependently hydrogen, linear or branched alkyl radical having 1 to 6carbon atoms, substituted or unsubstituted aryl radical having 6 to 30carbon atoms, substituted or unsubstituted heteroaryl radical having atotal of 5 to 18 carbon atoms and/or heteroatoms or silyl radical

orR³ and R⁴ together with A³ and A⁴ form an optionally substituted,unsaturated ring optionally interrupted by at least one furtherheteroatom and having a total of 5 to 18 carbon atoms and/orheteroatoms.

According to the invention, an unsaturated ring is a mono-, di- orpolyunsaturated, preferably monounsaturated, ring. According to theinvention, an aromatic ring is not covered by this definition. Moreparticularly, R³ and R⁴ together with A³ and A⁴ do not form a phenylring.

R² is more preferably a free electron pair if A² is N, or hydrogen if A²is C.

R³ is more preferably a free electron pair if A³ is N, or hydrogen orlinear or branched alkyl radical having 1 to 20 carbon atoms oroptionally substituted, saturated, unsaturated or aromatic ring having atotal of 5 to 18 carbon atoms and/or heteroatoms, more preferablybranched alkyl radical or o,o′-dialkylated phenyl ring, if A³ is C.

R⁴ is more preferably a free electron pair if A⁴ is N, or hydrogen orlinear or branched alkyl radical having 1 to 20 carbon atoms oroptionally substituted, saturated, unsaturated or aromatic ring having atotal of 5 to 18 carbon atoms and/or heteroatoms, more preferablybranched alkyl radical or o,o′-dialkylated phenyl ring, if A⁴ is C.

R³ and R⁴ most preferably form, together with A³ and A⁴ if A³ and A⁴ areeach C, an optionally substituted, unsaturated ring having a total of 5to 18 carbon atoms, though the case that A² and A⁵ are each N and R³ andR⁴ together with A³ and A⁴ form a phenyl ring is ruled out in accordancewith the invention.

R⁵ is more preferably a free electron pair if A⁵ is N, or hydrogen if A⁵is C.

In a further preferred embodiment, R⁶, R⁷, R⁸, R⁹ are each independentlyhydrogen or linear or branched alkyl radical having 1 to 20 carbon atomsor o,o′-dialkylated phenyl radicals, more preferably hydrogen.

In a further preferred embodiment, R⁶ and R⁷ or R⁷ and R⁸ or R⁸ and R⁹form, together with the phenyl ring, i.e. with the carbon atoms to whichthe radicals are attached, an unsaturated or aromatic, optionallysubstituted ring optionally interrupted by at least one heteroatom andhaving a total of 5, 6 or 7 carbon atoms and/or heteroatoms. The twoparticular radicals more preferably form, together with the phenyl ring,the following heterocycles: dibenzofuran, dibenzothiophene, fluorene,acridane, xanthene, thioxanthene, phenazine or phenoxazine.

Alternatively or additionally, R⁵ and R⁶ together may form a saturatedor unsaturated, linear or branched bridge optionally comprisingheteroatoms, aromatic units, heteroaromatic units and/or functionalgroups and having a total of 1 to 30 carbon atoms and/or heteroatoms, towhich is optionally fused a substituted or unsubstituted, five- toeight-membered, preferably six-membered, ring comprising carbon atomsand/or heteroatoms.

R²⁵ is, if present, preferably independently in accordance with theinvention, a linear or branched alkyl radical having 1 to 20 carbonatoms, a substituted or unsubstituted aryl radical having 6 to 30 carbonatoms, a substituted or unsubstituted heteroaryl radical having 5 to 18carbon atoms and/or heteroatoms, more preferably a linear alkyl radicalor a substituted or unsubstituted phenyl radical.

In a particularly preferred embodiment, the present invention relates toan inventive metal-carbene complex where M, n, Y, A², A³, A⁴, A⁵, R¹,R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, L, m and o are each defined as follows:

-   M is Ir,-   n is 1, 2 or 3,-   Y is NR¹,-   A², A³, A⁴, A⁵ are each independently N or C, where 2 A=nitrogen    atoms and at least one carbon atom is present between two nitrogen    atoms in the ring,-   R¹ is a linear or branched alkyl radical having 1 to 6 carbon atoms,    substituted or unsubstituted aryl radical having 6 to 30 carbon    atoms, substituted or unsubstituted heteroaryl radical having a    total of 5 to 18 carbon atoms and/or heteroatoms,-   R², R³, R⁴, R⁵ are each, if A², A³, A⁴ and/or A⁵ is N, a free    electron pair, or, if A², A³, A⁴ and/or A⁵ is C, each independently    hydrogen, linear or branched alkyl radical having 1 to 6 carbon    atoms, substituted or unsubstituted aryl radical having 6 to 30    carbon atoms, substituted or unsubstituted heteroaryl radical having    a total of 5 to 18 carbon atoms and/or heteroatoms,    or    R³ and R⁴ together with A³ and A⁴ form an optionally substituted,    unsaturated ring optionally interrupted by at least one further    heteroatom and having a total of 5 to 18 carbon atoms and/or    heteroatoms,-   R⁶, R⁷, R⁸, R⁹ are each independently hydrogen, linear or branched    alkyl radical optionally interrupted by at least one heteroatom,    optionally bearing at least one functional group and having 1 to 20    carbon atoms, substituted or unsubstituted aryl radical optionally    interrupted by at least one heteroatom, optionally bearing at least    one functional group and having 6 to 30 carbon atoms, substituted or    unsubstituted heteroaryl radical optionally interrupted by at least    one heteroatom, optionally bearing at least one functional group and    having a total of 5 to 18 carbon atoms and/or heteroatoms,-   L is a monoanionic bidentate ligand,-   m is 0,-   o is 0, 1 or 2.

The present invention more preferably relates to an inventivemetal-carbene complex where M, n, Y, A², A³, A⁴, A⁵, R¹, R², R³, R⁴, R⁵,R⁶, R⁷, R⁸, R⁹, L, m and o are each defined as follows:

-   M is Ir,-   n is 1, 2 or 3,-   Y is NR¹,-   A², A³, A⁴, A⁵ A² and A⁵ are each N and A³ and A⁴ are each C    or-   A² and A⁴ are each N and A³ and A⁵ are each C-   or-   A³ and A⁵ are each N and A² and A⁴ are each C,-   R¹ is a linear or branched alkyl radical having 1 to 6 carbon atoms,    substituted or unsubstituted phenyl radical, substituted or    unsubstituted heteroaryl radical having a total of 6 to 18 carbon    atoms and/or heteroatoms,-   R², R³, R⁴, R⁵ are each, if A², A³, A⁴ and/or A⁵ is N, a free    electron pair or, if A², A³, A⁴ and/or A⁵ is C, each independently    hydrogen, linear or branched alkyl radical having 1 to 6 carbon    atoms, substituted, especially o,o′-dialkylated, or unsubstituted    phenyl radical,    or    R³ and R⁴ together with A³ and A⁴ form an optionally substituted,    monounsaturated ring having a total of 5 to 7 carbon atoms,-   R⁶, R⁷, R⁸, R⁹ are each independently hydrogen, linear or branched    alkyl radical having 1 to 20 carbon atoms, o,o′-dialkylated aryl    radical having 6 to 30 carbon atoms,-   L is a monoanionic bidentate ligand,-   m is 0,-   o is 0, 1 or 2.

The further abovementioned preferred and particularly preferredembodiments apply correspondingly.

Very particularly preferred inventive metal-carbene complexes of thegeneral formula (I) are shown below.

The inventive homoleptic metal-carbene complexes may be present in theform of facial or meridional isomers, preference being given to thefacial isomers.

In the case of the heteroleptic metal-carbene complexes, four differentisomers may be present, preference being given to the pseudo-facialisomers.

The present invention additionally also relates to a process forpreparing the inventive metal-carbene complexes by contacting suitablecompounds comprising M with the appropriate ligands or ligandprecursors.

In a preferred embodiment of the process according to the invention, asuitable compound comprising the appropriate metal M, i.e. iridium orplatinum, preferably iridium, and appropriate carbene ligands,preferably in deprotonated form as the free carbene or in the form of aprotected carbene, for example as the silver-carbene complex, arecontacted. Suitable precursor compounds comprise the appropriatesubstituents R¹ to R⁹ and R²⁵ which should be present in the complexesof the general formula (I).

The present invention therefore relates more particularly to the processaccording to the invention wherein the ligand precursor used is acorresponding Ag-carbene complex.

In a further preferred embodiment of the process according to theinvention, the ligand precursors used are organic compounds which arereacted with suitable M-comprising compounds. The carbene can bereleased from precursors of the carbene ligands by removing volatilesubstances, for example lower alcohols such as methanol, ethanol, forexample at elevated temperature and/or under reduced pressure and/orusing molecular sieves which bind the alcohol molecules eliminated. Thisprocess is performed especially in the case of use of the compounds ofthe general formula (XII). Corresponding processes are known to thoseskilled in the art.

The present invention also relates to the process according to theinvention wherein the ligand precursor used is a compound of the generalformula (IV)

wherein Y, A², A³, A⁴, A⁵, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸ and R⁹ are each asalready defined above for the compounds of the general formula (I), andR²⁸ is defined as follows:

-   R²⁸ is independently SiR²⁹R³⁰R³¹, aryl, heteroaryl, alkyl,    cycloalkyl or heterocycloalkyl,-   R²⁹, R³⁹, R³¹ are each independently aryl, heteroaryl, alkyl,    cycloalkyl or heterocycloalkyl.

The definitions of aryl, heteroaryl, alkyl, cycloalkyl andheterocycloalkyl have been specified above.

In a particularly preferred embodiment, R²⁸ is alkyl, especiallyC₁-C₂₀-alkyl, preferably C₁-C₁₀-alkyl, more preferably C₁-C₈-alkyl, forexample methyl, ethyl, propyl such as n-propyl, isopropyl, butyl such asn-butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl or octyl.

R²⁸ in the compound of the general formula (IV) is most preferablymethyl or ethyl.

Compounds of the general formula (IV) are generally obtainable byprocesses known to those skilled in the art. In the case, which isparticularly preferred in accordance with the invention, that Y is NR¹,corresponding compounds of the general formula (IV) can be obtained byreacting compounds of the general formula (V)

with compounds of the general formula (VI)

HC(OR²⁸)₃  (VI),

where A², A³, A⁴, A⁵, R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R²⁸ areeach as already defined above for the compounds of the general formula(I) or (IV).

This preparation of the compounds of the general formula (IV) can beeffected in the presence or in the absence of a solvent. Suitablesolvents are specified below. In a preferred embodiment, the compoundsof the general formula (IV) are prepared in substance, or the compoundof the general formula (VI) is added in an excess, such that itfunctions as a solvent.

Compounds of the general formulae (V) and (VI) are commerciallyavailable and/or obtainable by processes known to those skilled in theart; for example, compounds of the general formula (V) are obtainable byreacting the appropriate chlorides with the appropriate amines.

The compounds of the general formula (IV) are prepared generally at atemperature of 10 to 150° C., preferably 40 to 120° C., more preferably60 to 110° C.

The reaction time is generally 2 to 48 hours, preferably 6 to 24 hours,more preferably 8 to 16 hours.

After the reaction has ended, the desired product can be isolated andpurified by customary processes known to those skilled in the art, forexample filtration, recrystallization, column chromatography, etc.

Appropriate compounds, especially complexes, comprising the appropriatemetal M, preferably iridium, are known to those skilled in the art.Particularly suitable compounds comprising platinum or iridium comprise,for example, ligands such as halides, preferably chloride,1,5-cyclooctadiene (COD), cyclooctene (COE), phosphines, cyanides,alkoxides, pseudohalides and/or alkyl.

Particularly preferred complexes comprising the appropriate metal,especially iridium, are selected from the group consisting of[Ir(COD)Cl]₂, [Ir(COE)₂Cl]₂ IrCl₃×H₂O, Ir(acac)₃, Ir(COD)₂BF₄,Ir(COD)₂BARF (BARF=tetrakis[3,5-bis(trifluoromethyl)phenyl]borate)),Pt(COD)Cl₂, Pt(acac)₂, [Pt(C₆H₁₀)Cl₂]₂, K₂PtCl₆ and mixtures thereof.

The carbene ligand precursors are deprotonated, preferably before thereaction, for example, by basic compounds known to those skilled in theart, for example basic metalates, basic metal acetates, acetylacetonatesor alkoxides, or bases such as KO^(t)Bu, NaO^(t)Bu, LiO^(t)Bu, NaH,silylamides, Ag₂O and phosphazene bases. Particular preference is givento deprotonating with Ag₂O to obtain the corresponding Ag-carbene, whichis reacted with the compound comprising M to give the inventivecomplexes.

The process according to the invention for preparing the complexes ofthe general formula (I) using the compounds of the general formula (IV)has the advantage that the compounds of the general formula (IV) arestable intermediates which can be handled readily and can be isolatedunder standard laboratory conditions. In addition, the compounds of thegeneral formula (IV) are soluble in customary organic solvents, suchthat the preparation of the inventive complexes of the general formula(I) in homogeneous solution is possible, such that a workup of thedesired product, i.e. of the complexes of the general formula (I) ismore readily possible, for example for isolation and/or purification.

The contacting is preferably effected in a solvent. Suitable solventsare known per se to those skilled in the art and are preferably selectedfrom the group consisting of aromatic or aliphatic solvents, for examplebenzene, toluene, xylene or mesitylene, cyclic or acyclic ethers, forexample dioxane or THF, alcohols, esters, amides, ketones, nitriles,halogenated compounds and mixtures thereof. Particularly preferredsolvents are toluene, xylenes, mesitylene and dioxane.

The molar ratio of metal-noncarbene complex used to carbene ligandprecursor used is generally 1:10 to 10:1, preferably 1:1 to 1:6, morepreferably 1:2 to 1:5.

The contacting is generally effected at a temperature of 20 to 200° C.,preferably 50 to 150° C., more preferably 60 to 130° C.

The reaction time depends on the desired carbene complex and isgenerally 0.02 to 50 hours, preferably 0.1 to 24 hours, more preferably1 to 12 hours.

The complexes of the general formula (I) obtained after the reaction canoptionally be purified by processes known to those skilled in the art,for example washing, crystallization or chromatography, and optionallyisomerized under conditions likewise known to those skilled in the art,for example with acid mediation, thermally or photochemically.

The aforementioned metal-carbene complexes and mixtures thereof areoutstandingly suitable as emitter molecules in organic light-emittingdiodes (OLEDs). Variations in the ligands make it possible to providecorresponding complexes which exhibit electroluminescence in the red,green and especially in the blue region of the electromagnetic spectrum.The inventive metal-carbene complexes of the general formula (I) aretherefore outstandingly suitable as emitter substances, since they haveemission (electroluminescence) in the visible region of theelectromagnetic spectrum, for example at 400 to 800 nm, preferably 400to 600 nm. The inventive complexes make it possible to provide compoundswhich have electroluminescence in the red, green and in the blue regionof the electromagnetic spectrum. It is thus possible, with the aid ofthe inventive complexes as emitter substances, to provide industriallyusable OLEDs.

In addition, the inventive metal-carbene complexes of the generalformula (I) can be used as matrix material, charge transport material,especially hole transport material, and/or charge blocker.

The inventive metal-carbene complexes of the general formula (I) arepreferably used as an emitter and/or hole transport material, morepreferably as an emitter.

Particular properties of the inventive metal-carbene complexes of thegeneral formula (I) are particularly good efficiencies and longlifetimes when used in OLEDs.

The present application therefore further provides an OLED comprising atleast one inventive metal-carbene complex of the general formula (I).The inventive metal-carbene complex of the general formula (I) is usedin the OLED preferably as an emitter, matrix material, charge transportmaterial, especially hole transport material, and/or charge blocker,more preferably as an emitter and/or hole transport material, mostpreferably as an emitter.

The present application also provides for the use of the metal-carbenecomplexes of the general formula (I) in OLEDs, preferably as an emitter,matrix material, charge transport material, especially hole transportmaterial, and/or charge blocker, more preferably as an emitter and/orhole transport material, most preferably as an emitter.

organic light diodes are in principle formed from a plurality of layers,e.g.:

-   -   anode (1)    -   hole-transporting layer (2)    -   light-emitting layer (3)    -   electron-transporting layer (4)    -   cathode (5)

It is, however, also possible that the OLED does not have all of thelayers mentioned; for example, an OLED comprising layers (1) (anode),(3) (light-emitting layer) and (5) (cathode) is likewise suitable, inwhich case the functions of layers (2) (hole-transporting layer) and (4)(electron-transporting layer) are assumed by the adjoining layers. OLEDshaving layers (1), (2), (3) and (5) or layers (1), (3), (4) and (5) arelikewise suitable.

The metal-carbene complexes of the general formula (I) are preferablyused as emitter molecules and/or matrix materials in the light-emittinglayer (3). The inventive metal-carbene complexs of the general formula(I) may also—in addition to use as emitter molecules and/or matrixmaterials in the light-emitting layer (3) or instead of use in thelight-emitting layer—also be used as a charge transport material in thehole-transporting layer (2) or in the electron-transporting layer (4)and/or as a charge blocker, preference being given to use as a chargetransport material in the hole-transporting layer (2) (hole transportmaterial).

The present application therefore further provides a light-emittinglayer comprising at least one of the inventive metal-carbene complexesof the general formula (I), preferably as emitter molecule. Preferredmetal-carbene complexes of the general formula (I) have already beenspecified above.

The metal-carbene complexes of the general formula (I) used inaccordance with the invention may be present in the light-emitting layerin substance, i.e. without further additions. However, it is alsopossible that, in addition to the metal-carbene complexes of the generalformula (I) used in accordance with the invention, further compounds arepresent in the light-emitting layer. For example, a fluorescent dye maybe present in order to alter the emission color of the metal-carbenecomplex used as the emitter molecule. In addition, a diluent material(matrix material) may be used. This diluent material may be a polymer,for example poly(N-vinylcarbazole) or polysilane. The diluent materialmay, however, likewise be a small molecule, for example 4,4′-N,N′-dicarbazolebiphenyl (CDP) or tertiary aromatic amines. When adiluent material is used, the proportion of the inventive metal-carbenecomplexes of the general formula (I) in the light-emitting layer isgenerally less than 40% by weight, preferably 3 to 30% by weight. Theinventive metal-carbene complexes of the general formula (I) arepreferably used in a matrix. The light-emitting layer thus preferablycomprises at least one inventive metal-carbene complex of the generalformula (I) and at least one matrix material.

Suitable matrix materials are—in addition to the aforementioned dilutionmaterials—in principle the materials specified hereinafter as hole andelectron transport materials, and also carbon complexes, for example thecarbene complexes of the formula (I) or the carbene complexes mentionedin WO 2005/019373. Particularly suitable are carbazole derivatives, forexample 4,4′-bis(carbazol-9-yl)-2,2′-dimethylbiphenyl (CDBP),4,4′-bis(carbazol-9-yl)biphenyl (CBP), 1,3-bis(N-carbazolyl)benzene(mCP), and the matrix materials specified in the following applications:WO2008/034758, WO2009/003919.

Dibenzofurans are additionally suitable as matrix materials, for examplethe dibenzo-furans disclosed in US 2007/0224446 A1, for example thosedibenzofurans in which at least one of the R1 to R8 radicals is aheterocyclic group, for example compound A-15, and the dibenzofuransdisclosed in WO 2009/069442 A1, WO 2010/090077 A1 and JP 2006/321750 A.

Further suitable matrix materials, which may be small molecules or(co)polymers of the small molecules mentioned, are specified in thefollowing publications:

WO2007108459 (H-1 to H-37), preferably H-20 to H-22 and H-32 to H-37,most preferably H-20, H-32, H-36, H-37, WO2008035571 A1 (Host 1 to Host6), JP2010135467 (compounds 1 to 46 and Host-1 to Host-39 and Host-43),WO2009008100 compounds No. 1 to No. 67, preferably No. 3, No. 4, No. 7to No. 12, No. 55, No. 59, No. 63 to No. 67, more preferably No. 4, No.8 to No. 12, No. 55, No. 59, No. 64, No. 65, and No. 67, WO2009008099compounds No. 1 to No. 110, WO2008140114 compounds 1-1 to 1-50,WO2008090912 compounds OC -7 to 0° C.-36 and the polymers of Mo-42 toMo-51, JP2008084913 H-1 to H-70, WO2007077810 compounds 1 to 44,preferably 1, 2, 4-6, 8, 19-22, 26, 28-30, 32, 36, 39-44, WO201001830the polymers of monomers 1-1 to 1-9, preferably of 1-3, 1-7, and 1-9,WO2008029729 the (polymers of) compounds 1-1 to 1-36, WO20100443342 HS-1to HS-101 and BH-1 to BH-17, preferably BH-1 to BH-17, JP2009182298 the(co)polymers based on the monomers 1 to 75, JP2009170764, JP2009135183the (co)polymers based on the monomers 1-14, WO2009063757 preferably the(co)polymers based on the monomers 1-1 to 1-26, WO2008146838 thecompounds a-1 to a-43 and 1-1 to 1-46, JP2008207520 the (co)polymersbased on the monomers 1-1 to 1-26, JP2008066569 the (co)polymers basedon the monomers 1-1 to 1-16, WO2008029652 the (co)polymers based on themonomers 1-1 to 1-52, WO2007114244 the (co)polymers based on themonomers 1-1 to 1-18, JP2010040830 the compounds HA-1 to HA-20, HB-1 toHB-16, HC-1 to HC-23 and the (co)polymers based on the monomers HD-1 toHD-12, JP2009021336, WO2010090077 the compounds 1 to 55, WO2010079678the compounds H1 to H42, WO2010067746, WO2010044342 the compounds HS-1to HS-101 and Poly-1 to Poly-4, JP2010114180 the compounds PH-1 toPH-36, US2009284138 the compounds 1 to 111 and H1 to H71, WO2008072596the compounds 1 to 45, JP2010021336 the compounds H-1 to H-38,preferably H-1, WO2010004877 the compounds H-1 to H-60, JP2009267255 thecompounds 1-1 to 1-105, WO2009104488 the compounds 1-1 to 1-38,WO2009086028, US2009153034, US2009134784, WO2009084413 the compounds 2-1to 2-56, JP2009114369 the compounds 2-1 to 2-40, JP2009114370 thecompounds 1 to 67, WO2009060742 the compounds 2-1 to 2-56, WO2009060757the compounds 1-1 to 1-76, WO2009060780 the compounds 1-1 to 1-70,WO2009060779 the compounds 1-1 to 1-42, WO2008156105 the compounds 1 to54, JP2009059767 the compounds 1 to 20, JP2008074939 the compounds 1 to256, JP2008021687 the compounds 1 to 50, WO2007119816 the compounds 1 to37, WO2010087222 the compounds H-1 to H-31, WO2010095564 the compoundsHOST-1 to HOST-61, WO2007108362, WO2009003898, WO2009003919,WO2010040777, US2007224446 and WO06128800.

In a particularly preferred embodiment, one or more compounds of thegeneral formula (X) specified hereinafter are used as matrix material.Preferred embodiments of the compounds of the general formula (X) arelikewise specified hereinafter.

The individual layers among the aforementioned layers of the OLED may inturn be formed from two or more layers. For example, thehole-transporting layer may be formed from one layer, into which holesare injected from the electrode, and a layer which transports the holesaway from the hole-injecting layer into the light-emitting layer. Theelectron-transporting layer may likewise consist of a plurality oflayers, for example of a layer in which electrons are injected throughthe electrode and a layer which receives electrons from theelectron-injecting layer and transports them into the light-emittinglayer. These layers mentioned are each selected according to factorssuch as energy level, thermal resistance and charge carrier mobility,and also energy difference of the layers mentioned with the organiclayers or the metal electrodes. The person skilled in the art is capableof selecting the construction of the OLEDs such that it is matchedoptimally to the heteroleptic complexes according to the presentinvention used as emitter substances in accordance with the invention.

In order to obtain particularly efficient OLEDs, the HOMO (highestoccupied molecular orbital) of the hole-transporting layer should bealigned to the work function of the anode, and the LUMO (lowestunoccupied molecular orbital) of the electron-transporting layer shouldbe aligned to the work function of the cathode.

The present application further provides an OLED comprising at least oneinventive light-emitting layer. The further layers in the OLED may beformed from any material which is typically used in such layers and isknown to those skilled in the art.

Suitable materials for the aforementioned layers (anode, cathode, holeand electron injection materials, hole and electron transport materialsand hole and electron blocker materials, matrix materials, fluorescenceand phosphorescence emitters) are known to those skilled in the art andare specified, for example, in H. Meng, N. Herron, Organic SmallMolecule Materials for Organic Light-Emitting Devices in OrganicLight-Emitting Materials and Devices, eds: Z. Li, H. Meng, Taylor &Francis, 2007, Chapter 3, pages 295 to 411.

The anode is an electrode which provides positive charge carriers. Itmay be composed, for example, of materials which comprise a metal, amixture of different metals, a metal alloy, a metal oxide or a mixtureof different metal oxides. Alternatively, the anode may be a conductivepolymer. Suitable metals comprise the metals of groups 11, 4, 5 and 6 ofthe Periodic Table of the Elements, and also the transition metals ofgroups 8 to 10. When the anode is to be transparent, mixed metal oxidesof groups 12, 13 and 14 of the Periodic Table of the Elements aregenerally used, for example indium tin oxide (ITO). It is likewisepossible that the anode (1) comprises an organic material, for examplepolyaniline, as described, for example, in Nature, Vol. 357, pages 477to 479 (Jun. 11, 1992). At least either the anode or the cathode shouldbe at least partly transparent in order to be able to emit the lightformed.

Suitable hole transport materials for layer (2) of the inventive OLEDare disclosed, for example, in Kirk-Othmer Encyclopedia of ChemicalTechnology, 4th Edition, Vol. 18, pages 837 to 860, 1996. Eitherhole-transporting molecules or polymers may be used as the holetransport material. Customarily used hole-transporting molecules areselected from the group consisting of4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (α-NPD),N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine(TPD), 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC),N,N′-bis(4-methylphenyl)-N,N′-bis(4-ethylphenyl)-[1,1′-(3,3′-dimethyl)biphenyl]-4,4′-diamine(ETPD), tetrakis(3-methylphenyl)-N,N,N′,N′-2,5-phenylenediamine (PDA),α-phenyl-4-N,N-diphenylaminostyrene (TPS), p-(diethylamino)benzaldehydediphenylhydrazone (DEH), triphenylamine (TPA),bis[4-(N,N-diethylamino)-2-methylphenyl](4-methylphenyl)methane (MPMP),1-phenyl-3-[p-(diethylamino)styryl]-5-[p-(diethylamino)phenyl]pyrazoline(PPR or DEASP), 1,2-trans-bis(9H-carbazol-9-yl)-cyclobutane (DCZB),N,N,N′,N′-tetrakis(4-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine (TTB),fluorine compounds such as2,2′,7,7′-tetra(N,N-di-tolyl)amino-9,9-spirobifluorene (spiro-TTB),N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)-9,9-spirobifluorene(spiro-NPB) and9,9-bis(4-(N,N-bis-biphenyl-4-yl-amino)phenyl-9H-fluorene, benzidinecompounds such as N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)benzidineand porphyrin compounds such as copper phthalocyanines. Customarily usedhole-transporting polymers are selected from the group consisting ofpolyvinylcarbazoles, (phenylmethyl)polysilanes and polyanilines. It islikewise possible to obtain hole-transporting polymers by dopinghole-transporting molecules into polymers such as polystyrene andpolycarbonate. Suitable hole-transporting molecules are the moleculesalready mentioned above.

In addition—in one embodiment—it is possible to use carbene complexes ashole conductor materials, in which case the band gap of the at least onehole conductor material is generally greater than the band gap of theemitter material used. In the context of the present application, bandgap is understood to mean the triplet energy. Suitable carbene complexesare, for example, the inventive carbine complexes of the general formula(I), carbene complexes as described in WO 2005/019373 A2, WO 2006/056418A2, WO 2005/113704, WO 2007/115970, WO 2007/115981 and WO 2008/000727.One example of a suitable carbene complex is Ir(DPBIC)₃ with theformula:

The hole-transporting layer may also be electronically doped in order toimprove the transport properties of the materials used, in order firstlyto make the layer thicknesses more generous (avoidance of pinholes/shortcircuits) and in order secondly to minimize the operating voltage of thedevice. Electronic doping is known to those skilled in the art and isdisclosed, for example, in W. Gao, A. Kahn, J. Appl. Phys., Vol. 94, No.1, 1 Jul. 2003 (p-doped organic layers); A. G. Werner, F. Li, K. Harada,M. Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett., Vol. 82, No. 25, 23Jun. 2003 and Pfeiffer et al., Organic Electronics 2003, 4, 89-103 andK. Walzer, B. Maennig, M. Pfeiffer, K. Leo, Chem. Soc. Rev. 2007, 107,1233. For example it is possible to use mixtures in thehole-transporting layer, in particular mixtures which lead to electricalp-doping of the hole-transporting layer. p-Doping is achieved by theaddition of oxidizing materials. These mixtures may, for example, be thefollowing mixtures: mixtures of the abovementioned hole transportmaterials with at least one metal oxide, for example MoO₂, MoO₃, WO_(x),ReO₃ and/or V₂O₅, preferably MoO₃ and/or ReO₃, more preferably ReO₃ ormixtures comprising the aforementioned hole transport materials and oneor more compounds selected from 7,7,8,8-tetracyanoquinodimethane (TCNQ),2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F₄-TCNQ),2,5-bis(2-hydroxyethoxy)-7,7,8,8-tetracyanoquinodimethane,bis(tetra-n-butylammonium)tetracyanodiphenoquinodimethane,2,5-dimethyl-7,7,8,8-tetracyanoquinodimethane, tetracyanoethylene,11,11,12,12-tetracyanonaphtho-2,6-quinodimethane,2-fluoro-7,7,8,8-tetracyanoquinodimethane,2,5-difluoro-7,7,8,8-tetracyanoquinodimethane,dicyanomethylene-1,3,4,5,7,8-hexafluoro-6H-naphthalen-2-ylidene)malononitrile(F₆-TNAP), Mo(tfd)₃ (from Kahn et al., J. Am. Chem. Soc. 2009, 131 (35),12530-12531), compounds as described in EP1988587 and in EP2180029 andquinone compounds as mentioned in EP 09153776.1.

Suitable electron-transporting materials for layer (4) of the inventiveOLEDs comprise metals chelated with oxinoid compounds, such astris(8-hydroxyquinolato)aluminum (Alq₃), compounds based onphenanthroline such as 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline(DDPA=BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen),2,4,7,9-tetraphenyl-1,10-phenanthroline,4,7-diphenyl-1,10-phenanthroline (DPA) or phenanthroline derivativesdisclosed in EP1786050, in EP1970371, or in EP1097981, and azolecompounds such as 2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole(PBD) and 3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole(TAZ). In addition, dibenzofurans are suitable as electron-transportingmaterials, for example the dibenzofurans disclosed in US 2007/0224446A1, for example those dibenzofurans in which at least one of the R1 toR8 radicals is a heterocyclic group, e.g. compound A-15, and thedibenzofurans disclosed in WO 2009/069442 A1, WO 2010/090077 A1 and JP2006/321750 A. Layer (4) may serve both to ease the electron transportand as a buffer layer or as a barrier layer in order to preventquenching of the exciton at the interfaces of the layers of the OLED.Layer (4) preferably improves the mobility of the electrons and reducesquenching of the exciton.

It is likewise possible to use mixtures of at least two materials in theelectron-transporting layer, in which case at least one material iselectron-conducting. Preferably, in such mixed electron-transportinglayers, at least one phenanthroline compound is used, preferably BCP, orat least one pyridine compound according to the formula (VIII) below,preferably a compound of the formula (VIIIaa) below. More preferably, inmixed electron-transporting layers, in addition to at least onephenanthroline compound, alkaline earth metal or alkali metalhydroxyquinolate complexes, for example Liq, are used. Suitable alkalineearth metal or alkali metal hydroxyquinolate complexes are specifiedbelow (formula VII).

The electron-transporting layer may also be electronically doped inorder to improve the transport properties of the materials used, inorder firstly to make the layer thicknesses more generous (avoidance ofpinholes/short circuits) and in order secondly to minimize the operatingvoltage of the device. Electronic doping is known to those skilled inthe art and is disclosed, for example, in W. Gao, A. Kahn, J. Appl.Phys., Vol. 94, No. 1, 1 Jul. 2003 (p-doped organic layers); A. G.Werner, F. Li, K. Harada, M. Pfeiffer, T. Fritz, K. Leo, Appl. Phys.Lett., Vol. 82, No. 25, 23 Jun. 2003 and Pfeiffer et al., OrganicElectronics 2003, 4, 89-103 and K. Walzer, B. Maennig, M. Pfeiffer, K.Leo, Chem. Soc. Rev. 2007, 107, 1233. For example, it is possible to usemixtures which lead to electrical n-doping of the electron-transportinglayer. n-Doping is achieved by the addition of reducing materials. Thesemixtures may, for example, be mixtures of the abovementioned electrontransport materials with alkali/alkaline earth metals or alkali/alkalineearth metal salts, for example Li, Cs, Ca, Sr, Cs₂CO₃, with alkali metalcomplexes, for example 8-hydroxyquinolatolithium (Liq), and with Y, Ce,Sm, Gd, Tb, Er, Tm, Yb, Li₃N, Rb₂CO₃, dipotassium phthalate, W(hpp)₄from EP 1786050, or with compounds as described in EP1837926 B1.

The present invention therefore also relates to an inventive OLED whichcomprises an electron-transporting layer comprising at least twodifferent materials, of which at least one material iselectron-conducting.

In a preferred embodiment, the electron-transporting layer comprises atleast one compound of the general formula (VII)

in which

-   R³² and R³³ are each independently F, C₁-C₈-alkyl, or C₆-C₁₄-aryl,    which is optionally substituted by one or more C₁-C₈-alkyl groups,    or two R³² and/or R³³ substituents together form a fused benzene    ring which is optionally substituted by one or more C₁-C₈-alkyl    groups;-   a and b are each independently 0, or 1, 2 or 3,-   M¹ is an alkaline metal atom or alkaline earth metal atom,-   p is 1 when M¹ is an alkali metal atom, p is 2 when M¹ is an alkalin    earth metal atom.

A very particularly preferred compound of the formula (VII) is

which may be present as a single species, or in other forms such asLi_(g)Q_(g) in which g is an integer, for example Li₆Q₆. Q is an8-hydroxyquinolate ligand or an 8-hydroxyquinolate derivative.

In a further preferred embodiment, the electron-transporting layercomprises at least one compound of the formula (VIII),

in which

-   R³⁴, R³⁵, R³⁶, R³⁷, R^(34′), R^(35′), R^(36′) and R^(37′) are each    independently H, C₁-C₁₈-alkyl, C₁-C₁₈-alkyl which is substituted by    E and/or interrupted by D, C₆-C₂₄-aryl, C₆-C₂₄-aryl which is    substituted by G, C₂-C₂₀-heteroaryl or C₂-C₂₀-heteroaryl which is    substituted by G,-   Q is an arylene or heteroarylene group, each of which is optionally    substituted by G;-   D is —CO—; —COO—; —S—; —SO—; —SO₂—; —O—; —NR⁴⁰—; —SiR⁴⁵R⁴⁶—;    —POR⁴⁷—; —CR³⁸═CR³⁹—; or —C≡C—; and-   E is −OR⁴⁴; —SR⁴⁴; —NR⁴⁰R⁴¹; —COR⁴³; —COOR⁴²; —CONR⁴⁰R⁴¹; —CN; or F;-   G is E, C₁-C₁₈-alkyl, C₁-C₁₈-alkyl which is interrupted by D,    C₁-C₁₈-perfluoroalkyl, C₁-C₁₈-alkoxy, or C₁-C₁₈-alkoxy which is    substituted by E and/or interrupted by D,    wherein-   R³⁸ and R³⁹ are each independently H, C₆-C₁₈-aryl; C₆-C₁₅-aryl which    is substituted by C₁-C₁₈-alkyl or C₁-C₁₈-alkoxy; C₁-C₁₈-alkyl; or    C₁-C₁₈-alkyl which is interrupted by —O—;-   R⁴⁰ and R⁴¹ are each independently C₆-C₁₈-aryl; C₆-C₁₈-aryl which is    substituted by C₁-C₁₈-alkyl or C₁-C₁₈-alkoxy; C₁-C₁₈-alkyl; or    C₁-C₁₈-alkyl which is interrupted by —O—; or-   R⁴⁰ and R⁴¹ together form a 6-membered ring;-   R⁴² and R⁴³ are each independently C₆-C₁₈-aryl; C₆-C₁₅-aryl which is    substituted by C₁-C₁₈-alkyl or C₁-C₁₈-alkoxy; C₁-C₁₈-alkyl; or    C₁-C₁₈-alkyl which is interrupted by —O—,-   R⁴⁴ is C₆-C₁₈-aryl; C₆-C₁₈-aryl which is substituted by C₁-C₁₈-alkyl    or C₁-C₁₈-alkoxy; C₁-C₁₈-alkyl; or C₁-C₁₈-alkyl which is interrupted    by —O—,-   R⁴⁵ and R⁴⁶ are each independently C₁-C₁₈-alkyl, C₆-C₁₈-aryl or    C₆-C₁₈-aryl which is substituted by C₁-C₁₈-alkyl,-   R⁴⁷ is C₁-C₁₈-alkyl, C₆-C₁₈-aryl or C₆-C₁₈-aryl which is substituted    by C₁-C₁₈-alkyl.

Preferred compounds of the formula (VIII) are compounds of the formula(VIIIa)

in which Q is:

R⁴⁸ is H or C₁-C₁₈-alkyl andR^(48′) is H, C₁-C₁₈-alkyl or

Particular preference is given to a compound of the formula (VIIIaa)

In a further, very particularly preferred embodiment, theelectron-transporting layer comprises a compound of the formula

and a compound of the formula

In a preferred embodiment, the electron-transporting layer comprises thecompound of the formula (VII) in an amount of 99 to 1% by weight,preferably 75 to 25% by weight, more preferably about 50% by weight,where the amount of the compounds of the formulae (VII) and the amountof the compounds of the formulae (VIII) adds up to a total of 100% byweight.

The preparation of the compounds of the formula (VIII) is described inJ. Kido et al., Chem. Commun. (2008) 5821-5823, J. Kido et al., Chem.Mater. 20 (2008) 5951-5953 and JP2008-127326, or the compounds can beprepared analogously to the processes disclosed in the aforementioneddocuments.

The preparation of the compounds of the formula (VII) is described, forexample, in Christoph Schmitz et al. Chem. Mater. 12 (2000) 3012-3019and WO00/32717, or the compounds can be prepared analogously to theprocesses disclosed in the aforementioned documents.

In a preferred embodiment, the invention relates to an inventive OLEDwherein the electron-transporting layer comprises at least onephenanthroline derivative and/or pyridine derivative.

In a further preferred embodiment, the invention relates to an inventiveOLED wherein the electron-transporting layer comprises at least onephenanthroline derivative and/or pyridine derivative and at least onealkali metal hydroxyquinolate complex.

In a further preferred embodiment, the invention relates to an inventiveOLED wherein the electron-transporting layer comprises at least onephenanthroline derivative and/or pyridine derivative and8-hydroxyquinolatolithium.

Some of the materials mentioned above as hole transport materials andelectron-transporting materials can fulfill several functions. Forexample, some of the electron-transporting materials are simultaneouslyhole-blocking materials if they have a low-lying HOMO.

The cathode (5) is an electrode which serves to introduce electrons ornegative charge carriers. The cathode may be any metal or nonmetal whichhas a lower work function than the anode. Suitable materials for thecathode are selected from the group consisting of alkali metals of group1, for example Li, Cs, alkaline earth metals of group 2, metals of group12 of the Periodic Table of the Elements, comprising the rare earthmetals and the lanthanides and actinides. In addition, metals such asaluminum, indium, calcium, barium, samarium and magnesium, andcombinations thereof, may be used. In addition, lithium-comprisingorganometallic compounds such as 8-hydroxyquinolatolithium (Liq), CsF,NaF, KF, Cs₂CO₃ or LiF may be applied between the organic layer and thecathode as an electron injection layer in order to reduce the operatingvoltage.

The OLED of the present invention may additionally comprise furtherlayers which are known to those skilled in the art. For example, a layerwhich eases the transport of the positive charge and/or matches the bandgaps of the layers to one another may be applied between the layer (2)and the light-emitting layer (3). Alternatively, this further layer mayserve as a protective layer. In an analogous manner, additional layersmay be present between the light-emitting layer (3) and the layer (4) inorder to ease the transport of the negative charge and/or to match theband gaps between the layers to one another. Alternatively, this layermay serve as a protective layer.

In a preferred embodiment, the inventive OLED, in addition to the layers(1) to (5), comprises at least one of the further layers mentionedbelow:

-   -   a hole injection layer between the anode (1) and the        hole-transporting layer (2);    -   a blocking layer for electrons between the hole-transporting        layer (2) and the light-emitting layer (3);    -   a blocking layer for holes between the light-emitting layer (3)        and the electron-transporting layer (4);    -   an electron injection layer between the electron-transporting        layer (4) and the cathode (5).

As already mentioned above, however, it is also possible that the OLEDdoes not have all of the layers (1) to (5) mentioned; for example, anOLED comprising layers (1) (anode), (3) (light-emitting layer) and (5)(cathode) is likewise suitable, in which case the functions of layers(2) (hole-transporting layer) and (4) (electron-transporting layer) areassumed by the adjoining layers. OLEDs having layers (1), (2), (3) and(5) or layers (1), (3), (4) and (5) are likewise suitable.

Those skilled in the art know how suitable materials have to be selected(for example on the basis of electrochemical investigations). Suitablematerials for the individual layers are known to those skilled in theart and disclosed, for example, in WO 00/70655.

In addition, it is possible that some or all of the layers (1), (2),(3), (4) and (5) have been surface-treated in order to increase theefficiency of charge carrier transport. The selection of the materialsfor each of the layers mentioned is preferably determined by obtainingan OLED having a high efficiency.

The inventive OLED can be produced by methods known to those skilled inthe art. In general, the OLED is produced by successive vapor depositionof the individual layers onto a suitable substrate. Suitable substratesare, for example, glass, inorganic materials such as ITO or IZO orpolymer films. For the vapor deposition, customary techniques may beused, such as thermal evaporation, chemical vapor deposition (CVD),physical vapor deposition (PVD) and others.

In an alternative process, the organic layers may be coated fromsolutions or dispersions in suitable solvents, in which case coatingtechniques known to those skilled in the art are employed. Suitablecoating techniques are, for example, spin-coating, the casting method,the Langmuir-Blodgett (“LB”) method, the inkjet printing method,dip-coating, letterpress printing, screen printing, doctor bladeprinting, slit-coating, roller printing, reverse roller printing, offsetlithography printing, flexographic printing, web printing, spraycoating, coating by a brush or pad printing, and the like. Among theprocesses mentioned, in addition to the aforementioned vapor deposition,preference is given to spin-coating, the inkjet printing method and thecasting method since they are particularly simple and inexpensive toperform.

In the case that layers of the OLED are obtained by the spin-coatingmethod, the casting method or the inkjet printing method, the coatingcan be obtained using a solution prepared by dissolving the compositionin a concentration of 0.0001 to 90% by weight in a suitable organicsolvent such as benzene, toluene, xylene, tetrahydrofuran,methyltetrahydrofuran, N,N-dimethylformamide, acetone, acetonitrile,anisole, dichloro-methane, dimethyl sulfoxide, water and mixturesthereof.

In general, the different layers have the following thicknesses: anode(2) 500 to 5000 Å, preferably 1000 to 2000 Å (ångström);hole-transporting layer (3) 50 to 1000 Å, preferably 200 to 800 Å;light-emitting layer (4) 10 to 1000 Å, preferably 100 to 800 Å;electron-transporting layer (5) 50 to 1000 Å, preferably 200 to 800 Å;cathode (6) 200 to 10 000 Å, preferably 300 to 5000 Å. In addition, itis likewise possible to combine several layers by mixing. For example,the hole-transporting material can be mixed with the materials of thelight-emitting layer and then applied together. The position of therecombination zone of holes and electrons in the inventive OLED and thusthe emission spectrum of the OLED may be influenced by the relativethickness and concentration ratios of each layer. This means that thethickness of the electron transport layer should preferably be selectedsuch that the electron/hole recombination zone is within thelight-emitting layer. The ratio of the layer thicknesses of theindividual layers in the OLED is dependent upon the materials used. Thelayer thicknesses of any additional layers used are known to thoseskilled in the art.

In a preferred embodiment, the present invention relates to an OLEDcomprising at least one inventive metal-carbene complex, and at leastone compound of the general formula (X)

in which

-   T is NR⁵⁷, S, O or PR⁵⁷, preferably S or O, more preferably O;-   R⁵⁷ is aryl, heteroaryl, alkyl, cycloalkyl or heterocycloalkyl;-   Q′ is —NR⁵⁸R⁵⁹, —P(O)R⁶⁰R⁶¹, —PR⁶²R⁶³, —S(O)₂R⁶⁴, —S(O)R⁶⁵, —SR⁶⁶ or    —OR⁶⁷, preferably —NR⁵⁸R⁵⁹; more preferably

-   -   in which    -   R⁶⁸, R⁶⁹ are each independently alkyl, cycloalkyl,        heterocycloalkyl, aryl or heteroaryl; preferably methyl,        carbazolyl, dibenzofuryl or dibenzothienyl;    -   y, z are each independently 0, 1, 2, 3 or 4, preferably 0 or 1;

-   R⁵⁵, R⁵⁶ are each independently alkyl, cycloalkyl, heterocycloalkyl,    aryl, heteroaryl, SiR⁷⁰R⁷¹R⁷², a Q′ group or a group with donor or    acceptor action;

-   a″ is 0, 1, 2, 3 or 4;

-   b′ is 0, 1, 2 or 3;

-   R⁵⁸, R⁵⁹ form, together with the nitrogen atom, a cyclic radical    which has 3 to 10 ring atoms and may be unsubstituted or substituted    by one or more substituents selected from alkyl, cycloalkyl,    heterocycloalkyl, aryl, heteroaryl and a group with donor or    acceptor action, and/or may be fused to one or more further cyclic    radicals having 3 to 10 ring atoms, where the fused radicals may be    unsubstituted or substituted by one or more substituents selected    from alkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl and a    group with donor or acceptor action;

-   R⁷⁰, R⁷¹, R⁷², R⁶⁰, R⁶¹, R⁶², R⁶³, R⁶⁴, R⁶⁶, R⁶⁶, R⁶⁷ are each    independently aryl, heteroaryl, alkyl, cycloalkyl or    heterocycloalkyl,    or    two units of the general formula (X) are bridged to one another via    a linear or branched, saturated or unsaturated bridge optionally    interrupted by at least one heteroatom, via a bond or via O.

Preference is given to compounds of the formula (X) in which:

T is S or O, preferably O, and

Q′ is

-   -   in which    -   R⁶⁸, R⁶⁹ are each independently alkyl, cycloalkyl,        heterocycloalkyl, aryl or heteroaryl; preferably methyl,        carbazolyl, dibenzofuryl or dibenzothienyl;    -   y, z are each independently 0, 1, 2, 3 or 4, preferably 0 or 1.

Particularly preferred compounds of the formula (X) have the followingformula (Xa):

in which the symbols and indices Q′, T, R⁵⁵, R⁵⁶, a″ and b′ are each asdefined above.

Very particularly preferred compounds of the formula (X) have theformula (Xaa):

in which the symbols and indices R⁶⁸, R⁶⁹ y, z, T, R⁵⁵, R⁵⁶, a″ and b′are each as defined above.

In a very particularly preferred embodiment, in formula (Xaa):

T is O or S, preferably O;a″ is 1;b′ is 0;y, z are each independently 0 or 1; andR⁶⁸, R⁶⁹ are each independently methyl, carbazolyl, dibenzofuryl ordibenzothienyl R⁵⁵ is substituted phenyl, carbazolyl, dibenzofuryl ordibenzothienyl.

In a further preferred embodiment, the compounds of the formula (X) havethe formula (XI) or (XI*):

in which

-   T is NR⁵⁷, S, O or PR⁵⁷;-   R⁵⁷ is aryl, heteroaryl, alkyl, cycloalkyl or heterocycloalkyl;-   Q′ is —NR⁵⁸R⁵⁹, —P(O)R⁶⁰R⁶¹, —PR⁶²R⁶³, —S(O)₂R⁶⁴, —S(O)R⁶⁵, —SR⁶⁶ or    —OR⁸⁷;-   R⁷⁰, R⁷¹, R⁷² are each independently aryl, heteroaryl, alkyl,    cycloalkyl, heterocycloalkyl, where at least one of the R⁷⁰, R⁷¹,    R⁷² radicals comprises at least two carbon atoms, or OR⁷³,-   R⁵⁵, R⁵⁶ are each independently alkyl, cycloalkyl, heterocycloalkyl,    aryl, heteroaryl, a Q group or a group with donor or acceptor    action;-   a′, b′ for the compound of the formula (XI): are each independently    0, 1, 2, 3; for the compound of the formula (XI*), a′ is 0, 1, 2 and    b′ is 0, 1, 2, 3, 4;-   R⁵⁸, R⁵⁹ form, together with the nitrogen atom, a cyclic radical    which has 3 to 10 ring atoms and may be unsubstituted or substituted    by one or more substituents selected from alkyl, cycloalkyl,    heterocycloalkyl, aryl, heteroaryl and a group with donor or    acceptor action and/or may be fused to one or more further cyclic    radicals having 3 to 10 ring atoms, where the fused radicals may be    unsubstituted or substituted by one or more substituents selected    from alkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl and a    group with donor or acceptor action;-   R⁷³ are each independently SiR⁷⁴R⁷⁵R⁷⁶, aryl, heteroaryl, alkyl,    cycloalkyl or heterocycloalkyl, optionally substituted by an OR⁷⁷    group,-   R⁷⁷ are each independently SiR⁷⁴R⁷⁵R⁷⁶, aryl, heteroaryl, alkyl,    cycloalkyl or heterocycloalkyl,-   R⁶⁰, R⁶¹, R⁶², R⁶³, R⁶⁴, R⁶⁵, R⁶⁶, R⁶⁷, R⁷⁴, R⁷⁵, R⁷⁶ are each    independently aryl, heteroaryl, alkyl, cycloalkyl or    heterocycloalkyl,    or    two units of the general formulae (XI) and/or (XI*) are bridged to    one another via a linear or branched, saturated or unsaturated    bridge optionally interrupted by at least one heteroatom or via O,    where this bridge in the general formulae (XI) and/or (XI*) is in    each case attached to the silicon atoms in place of R⁷¹.

The compounds of the general formula (X) can be used as a matrix(diluent material), hole/exciton blocker, electron/exciton blocker,electron transport material or hole transport material in combinationwith the complexes claimed, which then serve as emitters. InventiveOLEDs which include both at least one compound of the formula (X) and acompound of the formula (I) exhibit particularly good efficiencies andlifetimes. Depending on the function in which the compound of theformula (X) is used, it is present in pure form or in different mixingratios. In a particularly preferred embodiment, one or more compounds ofthe formula (X) are used as matrix material in the light-emitting layer.

For the compounds of the general formula (X), especially for the R⁵⁵ toR⁷⁷ radicals:

The terms aryl radical or group, heteroaryl radical or group, alkylradical or group, cycloalkyl radical or group, heterocycloalkyl radicalor group, alkenyl radical or group, alkynyl radical or group, and groupswith donor and/or acceptor action are each defined as follows:

An aryl radical (or group) is understood to mean a radical having a baseskeleton of 6 to 30 carbon atoms, preferably 6 to 18 carbon atoms, whichis formed from an aromatic ring or a plurality of fused aromatic rings.Suitable base skeletons are, for example, phenyl, naphthyl, anthracenylor phenanthrenyl, indenyl or fluorenyl. This base skeleton may beunsubstituted (which means that all carbon atoms which are substitutablebear hydrogen atoms), or may be substituted at one, more than one or allsubstitutable positions of the base skeleton.

Suitable substituents are, for example, deuterium, alkoxy radicals,aryloxy radicals, alkylamino groups, arylamino groups, carbazolylgroups, silyl groups, SiR⁷⁸R⁷⁹R⁸⁰, suitable silyl groups SiR⁷⁸1R⁷⁹R⁸⁰being specified below, alkyl radicals, preferably alkyl radicals having1 to 8 carbon atoms, more preferably methyl, ethyl or i-propyl, arylradicals, preferably C₆-aryl radicals, which may in turn be substitutedor unsubstituted, heteroaryl radicals, preferably heteroaryl radicalswhich comprise at least one nitrogen atom, more preferably pyridylradicals and carbazolyl radicals, alkenyl radicals, preferably alkenylradicals which bear one double bond, more preferably alkenyl radicalshaving one double bond and 1 to 8 carbon atoms, alkynyl radicals,preferably alkynyl radicals having one triple bond, more preferablyalkynyl radicals having one triple bond and 1 to 8 carbon atoms orgroups with donor or acceptor action. Suitable groups with donor oracceptor action are specified below. The substituted aryl radicals mostpreferably bear substituents selected from the group consisting ofmethyl, ethyl, isopropyl, alkoxy, heteroaryl, halogen, pseudohalogen andamino, preferably arylamino. The aryl radical or the aryl group ispreferably a C₆-C₁₈-aryl radical, more preferably a C₆-aryl radical,which is optionally substituted by at least one or more than one of theaforementioned substituents. The C₆-C₁₈-aryl radical, preferably C₆-arylradical, more preferably has none, one, two, three or four, mostpreferably none, one or two, of the aforementioned substituents.

A heteroaryl radical or a heteroaryl group is understood to meanradicals which differ from the aforementioned aryl radicals in that atleast one carbon atom in the base skeleton of the aryl radicals isreplaced by a heteroatom, and in that the base skeleton of theheteroaryl radicals preferably has 5 to 18 ring atoms. Preferredheteroatoms are N, O and S. Heteroaryl radicals suitable with particularpreference are nitrogen-containing heteroaryl radicals. Most preferably,one or two carbon atoms of the base skeleton are replaced byheteroatoms, preferably nitrogen. The base skeleton is especiallypreferably selected from systems such as pyridine, pyrimidine andfive-membered heteroaromatics such as pyrrole, furan, pyrazole,imidazole, thiophene, oxazole, thiazole, triazole. In addition, theheteroaryl radicals may be fused ring systems, for example benzofuryl,benzothienyl, benzopyrrolyl, dibenzofuryl, dibenzothienyl,phenanthrolinyl, carbazolyl radicals, azacarbazolyl radicals ordiazacarbazolyl radicals. The base skeleton may be substituted at one,more than one or all substitutable positions of the base skeleton.Suitable substituents are the same as have already been specified forthe aryl groups.

An alkyl radical or an alkyl group is understood to mean a radicalhaving 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, morepreferably 1 to 8, most preferably 1 to 4 carbon atoms. This alkylradical may be branched or unbranched and optionally be interrupted byone or more heteroatoms, preferably Si, N, O or S, more preferably N, Oor S. In addition, this alkyl radical may be substituted by one or moreof the substituents specified for the aryl groups. In addition, thealkyl radicals present in accordance with the invention may have atleast one halogen atom, for example F, Cl, Br or I, especially F. In afurther embodiment, the alkyl radicals present in accordance with theinvention may be fully fluorinated. It is likewise possible that thealkyl radical bears one or more (hetero)aryl groups. In the context ofthe present application, for example, benzyl radicals are thussubstituted alkyl radicals. In this context, all of the (hetero)arylgroups listed above are suitable. The alkyl radicals are more preferablyselected from the group consisting of methyl, ethyl, isopropyl,n-propyl, n-butyl, iso-butyl and tert-butyl, very particular preferencebeing given to methyl and ethyl.

A cycloalkyl radical or a cycloalkyl group is understood to mean aradical having 3 to 20 carbon atoms, preferably 3 to 10 carbon atoms,more preferably 3 to 8 carbon atoms. This base skeleton may beunsubstituted (which means that all carbon atoms which are substitutablebear hydrogen atoms) or substituted at one, more than one or allsubstitutable positions of the base skeleton. Suitable substituents arethe groups already mentioned above for the aryl radicals. It is likewisepossible that the cycloalkyl radical bears one or more (hetero)arylgroups. Examples of suitable cycloalkyl radicals are cyclopropyl,cyclopentyl and cyclohexyl.

A heterocycloalkyl radical or a heterocycloalkyl group is understood tomean radicals which differ from the aforementioned cycloalkyl radicalsin that at least one carbon atom in the base skeleton of the cycloalkylradicals is replaced by a heteroatom. Preferred heteroatoms are N, O andS. Most preferably, one or two carbon atoms of the base skeleton of thecycloalkyl radicals are replaced by heteroatoms. Examples of suitableheterocycloalkyl radicals are radicals derived from pyrrolidine,piperidine, piperazine, tetrahydrofuran, dioxane.

An alkenyl radical or an alkenyl group is understood to mean a radicalwhich corresponds to the aforementioned alkyl radicals having at leasttwo carbon atoms, with the difference that at least one C—C single bondof the alkyl radical is replaced by a C—C double bond. The alkenylradical preferably has one or two double bonds.

An alkynyl radical or an alkynyl group is understood to mean a radicalwhich corresponds to the aforementioned alkyl radicals having at leasttwo carbon atoms, with the difference that at least one C—C single bondof the alkyl radical is replaced by a C—C triple bond. The alkynylradical preferably has one or two triple bonds.

An SiR⁷⁸R⁷⁹R⁸⁰ group is understood to mean a silyl radical in which

R⁷⁸, R⁷⁹ and R⁸⁰ are each independently alkyl, cycloalkyl,heterocycloalkyl, aryl, heteroaryl or OR⁷³.

An SiR⁷⁴R⁷⁵R⁷⁶ group is understood to mean a silyl radical in which

R⁷⁴, R⁷⁵ and R⁷⁶ are each independently alkyl, cycloalkyl,heterocycloalkyl, aryl, heteroaryl or OR⁷³.

In the context of the present application, a group or a substituent withdonor or acceptor action is understood to mean the following groups:

Groups with donor action are understood to mean groups which have a +Iand/or +M effect, and groups with acceptor action are understood to meangroups which have a −I and/or −M effect. Preferred suitable groups areselected from C₁-C₂₀-alkoxy, C₆-C₃₀-aryloxy, C₁-C₂₀-alkylthio,C₆-C₃₀-arylthio, SiR⁸¹R⁸²R⁸³, OR⁷³, halogen radicals, halogenatedC₁-C₂₀-alkyl radicals, carbonyl (—CO(R⁸¹)), carbonylthio (—C═O(SR⁸¹)),carbonyloxy (—C═O(OR⁸¹))₇ oxycarbonyl (—OC═O(R⁸¹)), thiocarbonyl(—SC═O(R⁸¹)), amino (—NR⁸¹R⁸²), pseudohalogen radicals, amido(—C═O(NR⁸¹)), —NR⁸¹C═O(R⁸³), phosphonate (—P(O)(OR⁸¹)², phosphate(—OP(O)(OR⁸¹)₂), phosphine (—PR⁸¹R⁸²), phosphine oxide (—P(O)R⁸¹ ₂),sulfate (—OS(O)₂OR⁸¹), sulfoxide (—S(O)R⁸¹), sulfonate (—S(O)₂OR⁸¹),sulfonyl (—S(O)₂R⁸¹, sulfonamide (—S(O)₂NR⁸¹R⁸²), NO₂, boronic esters(—OB(OR⁸¹)₂), imino (—C═NR⁸¹R⁸²—))₇ borane radicals, stannane radicals,hydrazine radicals, hydrazone radicals, oxime radicals, nitroso groups,diazo groups, vinyl groups, sulfoximines, alanes, germanes, boroximesand borazines.

The R⁸¹, R⁸² and R⁸³ radicals mentioned in the aforementioned groupswith donor or acceptor action are each independently:

substituted or unsubstituted C₁-C₂₀-alkyl or substituted orunsubstituted C₆-C₃₀-aryl, or OR⁷⁶, suitable and preferred alkyl andaryl radicals having been specified above. The R⁸¹, R⁸² and R⁸³ radicalsare more preferably C₁-C₆-alkyl, e.g. methyl, ethyl or i-propyl, orphenyl. In a preferred embodiment—in the case of SiR⁸¹R⁸²R⁸³—R⁸¹, R⁸²and R⁸³ are preferably each independently substituted or unsubstitutedC₁-C₂₀-alkyl or substituted or unsubstituted aryl, preferably phenyl.

Preferred substituents with donor or acceptor action are selected fromthe group consisting of:

C₁- to C₂₀-alkoxy, preferably C₁-C₆-alkoxy, more preferably ethoxy ormethoxy; C₆-C₃₀-aryloxy, preferably C₆-C₁₀-aryloxy, more preferablyphenyloxy; SiR⁸¹R⁸²R⁸³ where R⁸¹, R⁸² and R⁸³ are preferably eachindependently substituted or unsubstituted alkyl or substituted orunsubstituted aryl, preferably phenyl; more preferably, at least one ofthe R⁸¹, R⁸² and R⁸³ radicals is substituted or unsubstituted phenyl,suitable substituents having been specified above; halogen radicals,preferably F, Cl, more preferably F, halogenated C₁-C₂₀-alkyl radicals,preferably halogenated C₁-C₆-alkyl radicals, most preferably fluorinatedC₁-C₆-alkyl radicals, e.g. CF₃, CH₂F, CHF₂ or C₂F₅; amino, preferablydimethylamino, diethylamino or diarylamino, more preferably diarylamino;pseudohalogen radicals, preferably CN, —C(O)OC₁-C₄-alkyl, preferably—C(O)OMe, P(O)R₂, preferably P(O)Ph₂.

Very particularly preferred substituents with donor or acceptor actionare selected from the group consisting of methoxy, phenyloxy,halogenated C₁-C₄-alkyl, preferably CF₃, CH₂F, CHF₂, C₂F₅, halogen,preferably F, CN, SiR⁸¹R⁸²R⁸³, suitable R⁸¹, R⁸² and R⁸³ radicalsalready having been specified, diarylamino (NR⁸⁴R⁸⁵ where R⁸⁴, R⁸⁵ areeach C₆-C₃₀-aryl), —C(O)OC₁-C₄-alkyl, preferably —C(O)OMe, P(O)Ph₂.

Halogen groups are preferably understood to mean F, Cl and Br, morepreferably F and Cl, most preferably F.

Pseudohalogen groups are preferably understood to mean CN, SCN and OCN,more preferably CN.

The aforementioned groups with donor or acceptor action do not rule outthe possibility that further radicals and substituents mentioned in thepresent application, but not included in the above list of groups withdonor or acceptor action, have donor or acceptor action.

The aryl radicals or groups, heteroaryl radicals or groups, alkylradicals or groups, cycloalkyl radicals or groups, heterocycloalkylradicals or groups, alkenyl radicals or groups and groups with donorand/or acceptor action may—as mentioned above—be substituted orunsubstituted. In the context of the present application, anunsubstituted group is understood to mean a group in which thesubstitutable atoms of the group bear hydrogen atoms. In the context ofthe present application, a substituted group is understood to mean agroup in which one or more substitutable atom(s) bear(s) a substituentin place of a hydrogen atom at least at one position. Suitablesubstituents are the substituents specified above for the aryl radicalsor groups.

When radicals having the same numbering occur more than once in thecompounds according to the present application, these radicals may eachindependently have the definitions specified.

The T radical in the compounds of the formula (X) is NR⁵⁷, S, O or PR⁵⁷,preferably NR⁵⁷, S or O, more preferably O or S, most preferably O.

The R⁵⁷ radical is aryl, heteroaryl, alkyl, cycloalkyl orheterocycloalkyl, preferably aryl, heteroaryl or alkyl, more preferablyaryl, where the aforementioned radicals may be unsubstituted orsubstituted. Suitable substituents have been specified above. R⁶⁵ ismore preferably phenyl which may be substituted by the aforementionedsubstituents or unsubstituted. R⁵⁷ is most preferably unsubstitutedphenyl.

The Q′ group in the compounds of the formula (X) is NR⁵⁸R⁵⁹,—P(O)R⁶⁰R⁶¹, —R⁶²R⁶³, —S(O)₂R⁶⁴, —S(O)R⁶⁵, —SR⁶⁶ or —OR⁶⁷; preferablyNR⁵⁸R⁵⁹, —P(O)R⁶⁰R⁶¹ or —OR⁶⁷, more preferably —NR⁵⁸R⁵⁹.

The R⁵⁸ to R⁶⁷ and R⁷⁴ to R⁷⁶ radicals are each defined as follows:

R⁵⁸, R⁵⁹ form, together with the nitrogen atom, a cyclic radical whichhas 3 to 10 ring atoms and may be unsubstituted or substituted by one ormore substituents selected from alkyl, cycloalkyl, heterocycloalkyl,aryl, heteroaryl and a group with donor or acceptor action and/or may befused to one or more further cyclic radicals having 3 to 10 ring atoms,where the fused radicals may be unsubstituted or substituted by one ormore substituents selected from alkyl, cycloalkyl, heterocycloalkyl,aryl, heteroaryl and a group with donor or acceptor action;

-   R⁶⁰, R⁶¹, R⁶², R⁶³, R⁶⁴, R⁶⁵, R⁶⁶, R⁶⁷, R⁷⁴, R⁷⁵, R⁷⁶ are each    independently aryl, heteroaryl, alkyl, cycloalkyl or    heterocycloalkyl, preferably aryl or heteroaryl, where the radicals    may be unsubstituted or substituted by one or more of the radicals    selected from alkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl    and a group with donor or acceptor action, more preferably    unsubstituted or substituted phenyl, suitable substituents having    been specified above, for example tolyl or a group of the formula

-   -   in which the T group and the R⁷⁰, R⁷¹ and R⁷² radicals are each        independently as defined for the compounds of the formula (XI)        or (XI*).        R⁶⁰, R⁶¹, R⁶², R⁶³, R⁶⁴, R⁶⁵, R⁶⁶ and R⁶⁷ are most preferably        each independently phenyl, tolyl or a group of the formula

in which T is NPh, S or O.

Examples of —NR⁵⁸R⁵⁹ groups suitable with preference are selected fromthe group consisting of pyrrolyl, 2,5-dihydro-1-pyrrolyl, pyrrolidinyl,indolyl, indolinyl, isoindolinyl, carbazolyl, azacarbazolyl,diazacarbazolyl, imidazolyl, imidazolinyl, benzimidazolyl, pyrazolyl,indazolyl, 1,2,3-triazolyl, benzotriazolyl, 1,2,4-triazolyl, tetrazolyl,1,3-oxazolyl, 1,3-thiazolyl, piperidyl, morpholinyl,9,10-dihydroacridinyl and 1,4-oxazinyl, where the aforementioned groupsmay be unsubstituted or substituted by one or more substituents selectedfrom alkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl and a groupwith donor or acceptor action; the —NR⁵⁸R⁵⁹ group is preferably selectedfrom carbazolyl, pyrrolyl, indolyl, imidazolyl, benzimidazolyl,azacarbazolyl and diazacarbazolyl, where the aforementioned groups maybe unsubstituted or substituted by one or more substituents selectedfrom alkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl and a groupwith donor or acceptor action; the —NR⁵⁸R⁵⁹ group is more preferablycarbazolyl which may be unsubstituted or substituted by one or moresubstituents selected from alkyl, cycloalkyl, heterocycloalkyl, aryl,heteroaryl and a group with donor or acceptor action.

Particularly preferred —NR⁵⁸R⁵⁹ groups are:

in which

-   R⁶⁸, R⁶⁹ are each independently alkyl, cycloalkyl, heterocycloalkyl,    aryl or heteroaryl; preferably methyl, carbazolyl, dibenzofuryl or    dibenzothienyl;-   y, z are each independently 0, 1, 2, 3 or 4, preferably 0 or 1;    for example:

-   -   in which X is NPh, S or O;

-   -   in which X is NPh, S or O,

Particularly preferred —P(O)R⁶⁰R⁶¹ groups are:

A particularly preferred PR⁶²R⁶³ group is:

Particularly preferred groups —S(O)₂R⁶⁴ and —S(O)R⁶⁵ are:

Particularly preferred groups —SR⁶⁶ and —OR⁶⁷ are:

-   -   in which T is in each case NPh, S or O.

R⁵⁵, R⁵⁶ in the compounds of the formula (X) are each independentlyalkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, a further A groupor a group with donor or acceptor action; preferably each independentlyalkyl, aryl, heteroaryl or a group with donor or acceptor action. Forexample, R⁵⁵ or R⁵⁶ may each independently be:

-   -   in which X is NPh, S or O.

In the compounds of the formula (X) a″ R⁵⁵ groups and/or b′ R⁵⁶ groupsmay be present, where a″ and b′ are:

a″ is 0, 1, 2, 3 or 4; preferably independently 0, 1 or 2;b′ is 0, 1, 2 or 3; preferably independently 0, 1 or 2.

Most preferably at least a″ or b′ is 0, very especially preferably a″and b′ are each 0 or a″ is 1 and b′ is 0.

R⁷³ in the compounds of the general formula (XI) is generallyindependently SiR⁷⁴R⁷⁵R⁷⁶, aryl, heteroaryl, alkyl, cycloalkyl orheterocycloalkyl, optionally substituted by an OR⁷⁷ group.

R⁷⁷ in compounds of the general formula (XI) is generally independentlyaryl, heteroaryl, alkyl, cycloalkyl or heterocycloalkyl.

The OR⁷⁷ substituent optionally present may generally be present in theradicals mentioned at all sites which appear suitable to the personskilled in the art.

In a further embodiment, two units of the general formula (XI) and/or(XI*) are bridged to one another via a linear or branched, saturated orunsaturated bridge optionally interrupted by at least one heteroatom orvia O, where this bridge in the general formula (XI) and/or (XI*) is ineach case attached to the silicon atoms in place of R⁷¹.

This bridge is preferably selected from the group consisting of —CH₂—,—C₂H₄—, —C₄H₈—, —C₆H₁₂—, —C₈H₁₆—, —C₉H₁₈—, —CH(C₈H₁₇)CH₂—,—C₂H₄(CF₂)₈C₂H₄—, —C≡C—, -1,4-(CH₂)₂-phenyl-(CH₂)₂—,1,3-(CH₂)₂-phenyl-(CH₂)₂—, -1,4-phenyl-, -1,3-phenyl-, —O—,—O—Si(CH₃)₂—O—, —O—Si(CH₃)₂—O—Si(CH₃)₂—O—, —O—In a preferred embodimentof the present application, the compounds of the general formula (X)have the general formula (XIa), (XIb), (XIc), (XId) or (XIe), i.e. theyare preferred embodiments of the compounds of the general formula (XI)or (XI*):

in which the Q′, T, R⁷⁰, R⁷¹, R⁷², R⁵⁵, R⁵⁶ radicals and groups, and a′and b′, are each as defined above.

In another embodiment preferred in accordance with the invention, R⁷⁰,R⁷¹ or R⁷² in the compounds of the general formula (XI) or (XI*) arearomatic units of the general formulae (XIi) and/or (XIi*)

where R⁵⁵, R⁵⁶, Q′, T, a′ and b′ are each as defined above.

The present invention therefore relates, in one embodiment, to aninventive OLED where R⁷⁰, R⁷¹ or R⁷² in the compounds of the generalformula (XI) or (XI*) are aromatic units of the general formulae (XIi)and/or (XIi*)

where R⁵⁶, R⁵⁶, Q′, T, a′ and b′ are each as defined above.

In a preferred embodiment, the present invention relates to an OLEDwherein the compound of the general formula (XI) or (XI*) is selectedfrom the following group:

In these particularly preferred compounds of the general formula (XI) or(XI*):

T is S or O, and R′ is H or CH₃; and

R⁷⁰, R⁷¹, R⁷² are each phenyl, carbazolyl, dibenzofuran ordibenzothiophene.

Further particularly suitable compounds of the general formula (XI) or(XI*) are:

In these particularly preferred compounds of the general formula (XI) or(XI*) too, T is O or S, preferably O.

Further inventive compounds of the general formula (XI) or (XI*)correspond to the following formula (XII)

In the general formula (XII), R⁷⁰, R⁷¹, R⁷² are each defined as follows:

No. R⁷⁰ R⁷¹ R⁷² 1 methyl methyl ethyl 2 methyl methyl i-propyl 3 methylmethyl n-propyl 4 methyl methyl n-butyl 5 methyl methyl i-butyl 6 methylmethyl t-butyl 7 methyl methyl n-pentyl 8 methyl methyl n-hexyl 9 methylmethyl —CH₂CH₂C(CH₃)₃ 10 methyl methyl n-C₈H₁₇ 11 methyl methyl i-C₈H₁₇12 methyl methyl n-C₁₀H₂₁ 13 methyl methyl n-C₁₂H₂₅ 16 methyl methyln-C₁₈H₃₇ 17 methyl methyl n-C₃₀H₆₁ 19 methyl methyl cyclohexyl 20 methylmethyl C(CH₃)₂Ph 21 methyl methyl —C(CH₃)₂CH(CH₃)₂ 22 methyl methyl—CCH₂CH(CH₃)(C₂H₅) 23 methyl methyl —CH₂CH(C₁₀H₂₁)₂ 24 methyl methyl—CH₂CH(C₁₂H₂₅)₂ 25 methyl methyl —CH₂CH₂(C₃F₆)CF₃ 26 methyl methyl—CH₂CH₂(C₇F₁₄)CF₃ 27 methyl methyl —CH₂CH₂(C₅F₁₀)CF₃ 29 methyl methyl—CH₂CH₂CF₃ 30 methyl methyl phenyl 31 methyl methyl 2-biphenyl 32 methylmethyl p-tolyl 33 methyl methyl C₆F₅ 34 methyl methyl 3,5-(CF₃)₂phenyl35 methyl methyl —CH₂C(CH₃)₂phenyl 36 methyl methyl 9-fluorenyl 37methyl methyl 3,6-di(tert-butyl)-9-fluorenyl 15 methyl methyl R⁸⁶ 38methyl methyl —OMe 39 methyl methyl —OEt 40 methyl methyl2,4,6-t-butylphenoxy 41 methyl methyl —O—tBu (tert-butoxy) 42 methylmethyl —OSiEt₃ 43 methyl ethyl ethyl 44 methyl ethyl phenyl 45 methylethyl R⁸⁶ 46 methyl n-propyl n-propyl 47 methyl n-propyl phenyl 48methyl n-propyl R⁸⁶ 49 methyl i-propyl i-propyl 50 methyl i-propylphenyl 51 methyl i-propyl R⁸⁶ 52 methyl n-butyl n-butyl 53 methyln-butyl phenyl 54 methyl n-butyl R⁸⁶ 55 methyl i-butyl i-butyl 56 methyli-butyl phenyl 57 methyl i-butyl R⁸⁶ 58 methyl t-butyl t-butyl 59 methylt-butyl phenyl 60 methyl t-butyl R⁸⁶ 61 methyl n-pentyl n-pentyl 62methyl n-pentyl n-hexyl 63 methyl n-pentyl phenyl 64 methyl n-pentyl R⁸⁶65 methyl n-hexyl hexyl 66 methyl n-hexyl phenyl 67 methyl n-hexyl R⁸⁶68 methyl n-heptyl R⁸⁶ 69 methyl n-octyl R⁸⁶ 70 methyl n-decyl R⁸⁶ 71methyl n-C₁₂H₂₅ R⁸⁶ 72 methyl n-C₁₈H₃₇ R⁸⁶ 73 methyl n-C₂₂H₄₅ R⁸⁶ 74methyl n-C₃₀H₆₁ R⁸⁶ 75 methyl cyclopentyl cyclopentyl 76 methylcyclopentyl phenyl 77 methyl cyclopentyl R⁸⁶ 78 methyl cyclohexylcyclohexyl 79 methyl cyclohexyl phenyl 80 methyl cyclohexyl R⁸⁶ 81methyl —CF₂CHF₂ R⁸⁶ 82 methyl —CH₂CH₂CF₃ R⁸⁶ 83 methyl —CH₂CH₂(CF₂)₃CF₃R⁸⁶ 84 methyl —CH₂CH₂(CF₂)₅CF₃ R⁸⁶ 85 methyl —CH₂CH₂(CF₂)₇CF₃ R⁸⁶ 86methyl phenyl phenyl 87 methyl phenyl p-tolyl 89 methyl phenyl mesityl90 methyl phenyl R⁸⁶ 91 methyl p-tolyl p-tolyl 92 methyl p-tolyl R⁸⁶ 93methyl mesityl mesityl 94 methyl mesityl R5 95 methyl R⁸⁶ R⁸⁶ 96 methylmethoxy methoxy 97 methyl ethoxy ethoxy 98 methyl —OSiEt₃ —OSiEt₃ 99methyl —O—SiMe₂—CH₂CH₂(CF₂)₄CF₃ —O—SiMe₂—CH₂CH₂(CF₂)₄CF₃ 100 ethyl ethylethyl 101 ethyl ethyl n-propyl 102 ethyl ethyl i-propyl 103 ethyl ethyln-butyl 104 ethyl ethyl i-butyl 105 ethyl ethyl t-butyl 106 ethyl ethylphenyl 107 ethyl ethyl R5 108 ethyl phenyl phenyl 109 ethyl phenyl R⁸⁶110 ethyl R⁸⁶ R⁸⁶ 111 ethyl ethoxy ethoxy 112 n-propyl n-propyl n-propyl113 n-propyl n-propyl phenyl 114 n-propyl n-propyl R⁸⁶ 115 n-propylphenyl phenyl 116 n-propyl phenyl R⁸⁶ 117 n-propyl R⁸⁶ R⁸⁶ 118 i-propyli-propyl i-propyl 119 i-propyl i-propyl phenyl 120 i-propyl i-propyl R⁸⁶121 i-propyl i-propyl 2-biphenyl 122 i-propyl i-propyl ethoxy 123i-propyl phenyl phenyl 124 i-propyl phenyl R⁸⁶ 125 i-propyl R⁸⁶ R⁸⁶ 126n-butyl n-butyl n-butyl 127 n-butyl n-butyl phenyl 128 n-butyl n-butylR⁸⁶ 129 n-butyl n-hexyl R⁸⁶ 130 n-butyl phenyl phenyl 131 n-butyl phenylR⁸⁶ 132 n-butyl R⁸⁶ R⁸⁶ 133 sec-butyl sec-butyl sec-butyl 134 sec-butylsec-butyl phenyl 135 sec-butyl sec-butyl R⁸⁶ 136 sec-butyl phenyl phenyl137 sec-butyl phenyl R⁸⁶ 138 sec-butyl R⁸⁶ R⁸⁶ 139 i-butyl i-butyli-butyl 140 i-butyl i-butyl n-C₈H₁₇ 141 i-butyl i-butyl n-C₁₈H₃₇ 142i-butyl i-butyl phenyl 143 i-butyl i-butyl R⁸⁶ 144 i-butyl phenyl phenyl145 i-butyl phenyl R⁸⁶ 146 i-butyl R⁸⁶ R⁸⁶ 147 t-butyl t-butyl t-butyl148 t-butyl t-butyl n-C₈H₁₇ 149 t-butyl t-butyl phenyl 150 t-butylt-butyl R⁸⁶ 151 t-butyl phenyl phenyl 152 t-butyl phenyl R5 153 t-butylR⁸⁶ R⁸⁶ 154 n-pentyl n-pentyl n-pentyl 155 n-pentyl n-pentyl phenyl 156n-pentyl n-pentyl R⁸⁶ 157 n-pentyl phenyl phenyl 158 n-pentyl phenyl R⁸⁶159 n-pentyl R⁸⁶ R⁸⁶ 160 cyclopentyl cyclopentyl cyclopentyl 161cyclopentyl cyclopentyl phenyl 162 cyclopentyl cyclopentyl R⁸⁶ 163cyclopentyl phenyl phenyl 164 cyclopentyl phenyl R⁸⁶ 165 cyclopentyl R⁸⁶R⁸⁶ 166 n-hexyl n-hexyl n-hexyl 167 n-hexyl n-hexyl phenyl 168 n-hexyln-hexyl R₈₆ 169 n-hexyl phenyl phenyl 170 n-hexyl phenyl R⁸⁶ 171 n-hexylR⁸⁶ R⁸⁶ 172 —CH₂CH₂C(CH₃)₃ —CH₂CH₂C(CH₃)₃ —CH₂CH₂C(CH₃)₃ 173—CH₂CH₂C(CH₃)₃ —CH₂CH₂C(CH₃)₃ R⁸⁶ 174 —CH₂CH₂C(CH₃)₃ R⁸⁶ R⁸⁶ 175 t-hexylt-hexyl t-hexyl 176 t-hexyl t-hexyl R⁸⁶ 177 t-hexyl R⁸⁶ R⁸⁶ 178 n-heptyln-heptyl n-heptyl 179 n-heptyl n-heptyl R⁸⁶ 180 n-heptyl R⁸⁶ R⁸⁶ 181n-octyl n-octyl n-octyl 182 n-octyl n-octyl R⁸⁶ 183 n-octyl R⁸⁶ R⁸⁶ 184i-octyl i-octyl i-octyl 185 i-octyl i-octyl R⁸⁶ 186 i-octyl R⁸⁶ R⁸⁶ 187n-nonyl n-nonyl n-nonyl 188 n-nonyl n-nonyl R⁸⁶ 189 n-nonyl R⁸⁶ R⁸⁶ 190cyclohexyl cyclohexyl cyclohexyl 191 cyclohexyl cyclohexyl R⁸⁶ 192cyclohexyl R⁸⁶ R⁸⁶ 193 cyclooctyl cyclooctyl cyclooctyl 194 cyclooctylcyclooctyl R⁸⁶ 195 cyclooctyl R⁸⁶ R⁸⁶ 196 n-C₁₀H₂₁ n-C₁₀H₂₁ n-C₁₀H₂₁ 197n-C₁₀H₂₁ n-C₁₀H₂₁ R⁸⁶ 198 n-C₁₀H₂₁ R⁸⁶ R⁸⁶ 199 n-C₁₁H₂₃ n-C₁₁H₂₃n-C₁₁H₂₃ 200 n-C₁₁H₂₃ n-C₁₁H₂₃ R⁸⁶ 201 n-C₁₁H₂₃ R⁸⁶ R⁸⁶ 202 n-C₁₂H₂₅n-C₁₂H₂₅ n-C₁₂H₂₅ 203 n-C₁₂H₂₅ n-C₁₂H₂₅ R⁸⁶ 204 n-C₁₂H₂₅ R⁸⁶ R⁸⁶ 205n-C₁₄H₂₉ n-C₁₄H₂₉ n-C₁₄H₂₉ 206 n-C₁₄H₂₉ n-C₁₄H₂₉ R⁸⁶ 207 n-C₁₄H₂₉ R⁸⁶R⁸⁶ 208 n-C₁₆H₃₃ n-C₁₆H₃₃ n-C₁₆H₃₃ 209 n-C₁₆H₃₃ n-C₁₆H₃₃ R⁸⁶ 210n-C₁₆H₃₃ R⁸⁶ R⁸⁶ 211 n-C₁₈H₃₇ n-C₁₈H₃₇ R⁸⁶ 212 n-C₁₈H₃₇ R⁸⁶ R⁸⁶ 213n-C₁₈H₃₇ OEt OEt 214 n-C₁₈H₃₇ R⁸⁶ OMe 215 n-C₂₀H₄₁ n-C₂₀H₄₁ n-C₂₀H₄₁ 216n-C₂₀H₄₁ n-C₂₀H₄₁ R⁸⁶ 217 n-C₂₀H₄₁ R⁸⁶ R⁸⁶ 218 n-C₂₂H₄₅ n-C₂₂H₄₅n-C₂₂H₄₅ 219 n-C₂₂H₄₅ n-C₂₂H₄₅ R⁸⁶ 220 n-C₂₂H₄₅ R⁸⁶ R₈₆ 221 n-C₂₆H₅₃n-C₂₆H₅₃ n-C₂₆H₅₃ 222 n-C₂₆H₅₃ n-C₂₆H₅₃ R⁸⁶ 223 n-C₂₆H₅₃ R⁸⁶ R⁸⁶ 224n-C₃₀H₆₁ n-C₃₀H₆₁ n-C₃₀H₆₁ 225 n-C₃₀H₆₁ n-C₃₀H₆₁ R⁸⁶ 226 n-C₃₀H₆₁ R⁸⁶R⁸⁶ 227 —CH₂-cyclohexyl —CH₂-cyclohexyl R⁸⁶ 228 —CH₂CH₂CF₃ —CH₂CH₂CF₃—CH₂CH₂CF₃ 229 —CH₂CH₂CF₃ —CH₂CH₂CF₃ R⁸⁶ 230 —CH₂CH₂CF₃ R⁸⁶ R⁸⁶ 231—CH₂CH₂(CF₂)₃CF₃ —CH₂CH₂(CF₂)₃CF₃ —CH₂CH₂(CF₂)₃CF₃ 232 —CH₂CH₂(CF₂)₃CF₃—CH₂CH₂(CF₂)₃CF₃ R⁸⁶ 233 —CH₂CH₂(CF₂)₃CF₃ R⁸⁶ R⁸⁶ 234 —CH₂CH₂(CF₂)₅CF₃—CH₂CH₂(CF₂)₅CF₃ —CH₂CH₂(CF₂)₅CF₃ 235 —CH₂CH₂(CF₂)₅CF₃ —CH₂CH₂(CF₂)₅CF₃R⁸⁶ 236 —CH₂CH₂(CF₂)₅CF₃ R⁸⁶ R⁸⁶ 237 —CH₂CH₂(CF₂)₇CF₃ —CH₂CH₂(CF₂)₇CF₃—CH₂CH₂(CF₂)₇CF₃ 238 —CH₂CH₂(CF₂)₇CF₃ —CH₂CH₂(CF₂)₇CF₃ R⁸⁶ 239—CH₂CH₂(CF₂)₇CF₃ R⁸⁶ R⁸⁶ 240 —CH₂CH₂(CF₂)₉CF₃ —CH₂CH₂(CF₂)₉CF₃—CH₂CH₂(CF₂)₉CF₃ 241 —CH₂CH₂(CF₂)₉CF₃ —CH₂CH₂(CF₂)₉CF₃ R⁸⁶ 242—CH₂CH₂(CF₂)₉CF₃ R⁸⁶ R⁸⁶ 243 —CH₂CH₂(CF₂)₁₁CF₃ —CH₂CH₂(CF₂)₁₁CF₃—CH₂CH₂(CF₂)₁₁CF₃ 244 —CH₂CH₂(CF₂)₁₁CF₃ —CH₂CH₂(CF₂)₁₁CF₃ R⁸⁶ 245—CH₂CH₂(CF₂)₁₁CF₃ R⁸⁶ R⁸⁶ 246 —CF₂CHF₂ —CF₂CHF₂ —CF₂CHF₂ 247 —CF₂CHF₂—CF₂CHF₂ R⁸⁶ 248 —CF₂CHF₂ R⁸⁶ R⁸⁶ 249 —(CF₂)₃CHF₂ —(CF₂)₃CHF₂—(CF₂)₃CHF₂ 250 —(CF₂)₃CHF₂ —(CF₂)₃CHF₂ R⁸⁶ 251 —(CF₂)₃CHF₂ R⁸⁶ R⁸⁶ 14phenyl phenyl phenyl 252 phenyl phenyl p-tolyl 253 phenyl phenyl m-tolyl254 phenyl phenyl o-tolyl 255 phenyl phenyl 2-xylyl 256 phenyl phenyl5-xylyl 257 phenyl phenyl mesityl 258 phenyl phenyl 9-fluorenyl 18phenyl phenyl R⁸⁶ 259 phenyl phenyl —O—tBu (tert-butoxy) 260 phenylp-tolyl p-tolyl 261 phenyl m-tolyl m-tolyl 262 phenyl o-tolyl o-tolyl263 phenyl 2-xylyl 2-xylyl 264 phenyl 5-xylyl 5-xylyl 265 phenyl mesitylmesityl 266 phenyl R⁸⁶ R⁸⁶ 267 phenyl ethoxy ethoxy 268 p-tolyl p-tolylp-tolyl 269 p-tolyl p-tolyl R⁸⁶ 270 p-tolyl R⁸⁶ R⁸⁶ 271 m-tolyl m-tolylm-tolyl 272 m-tolyl m-tolyl R⁸⁶ 273 o-tolyl o-tolyl o-tolyl 274 o-tolylo-tolyl R⁸⁶ 275 2-xylyl 2-xylyl 2-xylyl 276 2-xylyl 2-xylyl R⁸⁶ 2775-xylyl 5-xylyl 5-xylyl 278 5-xylyl 5-xylyl R⁸⁶ 279 mesityl mesitylmesityl 280 mesityl mesityl R⁸⁶ 281 C₆F₅ C₆F₅ C₆F₅ 282 C₆F₅ C₆F₅ R⁸⁶ 283C₆F₅ R⁸⁶ R⁸⁶ 284 R⁸⁶ R⁸⁶ R⁸⁶ 285 R⁸⁶ ethoxy ethoxy 286 R⁸⁶ n-butoxyn-butoxy 287 R⁸⁶ R⁸⁶ methoxy 288 R⁸⁶ R⁸⁶ ethoxy 289 R⁸⁶ R⁸⁶ OSiMe₃ 290R⁸⁶ R⁸⁶ —(CH₂)₁₁O—(CH₂)₂OCH₃ 291 methoxy methoxy methoxy 292 ethoxyethoxy ethoxy 293 i-propoxy i-propoxy i-propoxy 294 t-butoxy t-butoxyt-butoxy 295 OSiMe₃ OSiMe₃ OSiMe₃ 296 cyclobutyl methyl 297 cyclobutylR⁸⁶ 298 cyclobutyl p-methoxyphenyl 299 cyclopentyl methyl 300cyclopentyl R⁸⁶ 301 cyclohexyl methyl 302 cyclohexyl R⁸⁶ In this table,

Particularly preferred compounds in which two units of the generalformulae (XI) and/or (XI*) are bridged to one another via a linear orbranched, saturated or unsaturated bridge optionally interrupted by atleast one heteroatom or via O, where this bridge in the general formulae(XI) and/or (XI*) is in each case attached to the silicon atoms in placeof R⁷¹, correspond to the general formula (XIII)

In formula (XIII), U, R⁷⁰, R⁷¹, R⁷², R⁸⁷, R⁸⁸ and R⁸⁹ are each definedas follows:

No. R70 R71 R72 R87 R88 R89 U 303 methyl R⁸⁶ R⁸⁶ methyl R5 R⁸⁶ —CH₂— 304methyl methyl R⁸⁶ methyl methyl R⁸⁶ —CH₂— 305 R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶—CH₂— 306 methyl R⁸⁶ R⁸⁶ methyl R5 R⁸⁶ —C₂H₄— 307 methyl methyl R⁸⁶methyl methyl R⁸⁶ —C₂H₄— 308 R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ —C₂H₄— 309 methylR⁸⁶ R⁸⁶ methyl R⁸⁶ R⁸⁶ —C₃H₆— 310 methyl methyl R⁸⁶ methyl methyl R⁸⁶—C₃H₆— 311 R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸ —C₃H₆— 312 methyl R⁸⁶ R⁸⁶ methyl R⁸⁶R⁸⁶ —C₄H₈— 313 methyl methyl R⁸⁶ methyl methyl R⁸⁶ —C₄H₈— 314 R⁸⁶ R⁸⁶R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ —C₄H₈— 315 methyl R⁸⁶ R⁸⁶ methyl R⁸⁶ R⁸⁶ —C₆H₁₂— 316methyl methyl R⁸⁶ methy methyl R⁸⁶ —C₆H₁₂— 317 R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶—C₆H₁₂— 318 methyl R⁸⁶ R⁸⁶ methyl R⁸⁶ R⁸⁶ —C₈H₁₆— 319 methyl methyl R⁸⁸methyl methyl R⁸⁸ —C₈H₁₆— 320 R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁸ —C₈H₁₆— 321 methylR⁸⁶ R⁸⁶ methyl R⁸⁶ R⁸⁶ —C₉H₁₈ 322 methyl methyl R⁸⁶ methyl methyl R⁸⁶—C₉H₁₈— 323 R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ —C₉H₁₈— 324 R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶—CH(C₈H₁₇)CH₂— 325 methyl R⁸⁶ R⁸⁶ methyl R⁸⁶ R⁸⁶ —C₂H₄(CF₂)₈C₂H₄— 326methyl methyl R⁸⁶ methyl methyl R⁸⁶ —C₂H₄(CF₂)₈C₂H₄— 327 R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶R⁸⁶ R⁸⁶ —C₂H₄(CF₂)₈C₂H₄— 328 methyl R⁸⁶ R⁸⁶ methyl R⁸⁶ R⁸⁶ —C≡C— 329methyl methyl R⁸⁶ methyl methyl R⁸⁶ —C≡C— 330 R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶—C≡C— 331 methyl R⁸⁶ R⁸⁶ methyl R⁸⁶ R⁸⁶ —1,4-(CH₂)₂-phenyl-(CH₂)₂— 332methyl methyl R⁸⁶ methyl methyl R⁸⁶ —1,4-(CH₂)₂-phenyl-(CH₂)₂— 333 R⁸⁶R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ —1,4-(CH₂)₂-phenyl-(CH₂)₂— 334 methyl R⁸⁶ R⁸⁶ methylR⁸⁶ R⁸⁶ —1,3-(CH₂)₂-phenyl-(CH₂)₂— 335 methyl methyl R⁸⁶ methyl methylR⁸⁶ —1,3-(CH₂)₂-phenyl-(CH₂)₂— 336 R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶—1,3-(CH₂)₂-phenyl-(CH₂)₂— 337 methyl R⁸⁶ R⁸⁶ methyl R⁸⁶ R⁸⁶—1,4-(CH₂)₃-phenyl-(CH₂)₃— 338 methyl methyl R⁸⁶ methyl methyl R⁸⁶—1,4-(CH₂)₃-phenyl-(CH₂)₃— 339 R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶—1,4-(CH₂)₃-phenyl-(CH₂)₃— 340 methyl R⁸⁶ R⁸⁶ methyl R⁸⁶ R⁸⁶—1,3-(CH₂)₃-phenyl-(CH₂)₃— 341 methyl methyl R⁸⁶ methyl methyl R⁸⁶—1,3-(CH₂)₃-phenyl-(CH₂)₃— 342 R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶—1,3-(CH₂)₃-phenyl-(CH₂)₃— 343 methyl R⁸⁶ R⁸⁶ methyl R⁸⁶ R⁸⁶-1,4-phenyl- 344 methyl methyl R⁸⁶ methyl methyl R⁸⁶ -1,4-phenyl- 345R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ -1,4-phenyl- 346 methyl R⁸⁶ R⁸⁶ methyl R⁸⁶ R⁸⁶-1,3-phenyl- 347 methyl methyl R⁸⁶ methyl methyl R⁸⁶ -1,3-phenyl- 348R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ -1,3-phenyl- 28 methyl methyl R⁸⁶ methyl methylR⁸⁶ —O— 349 methyl R⁸⁶ R⁸⁶ methyl R⁸⁶ R⁸⁶ —O— 350 methyl methyl R⁸⁶methyl methyl R⁸⁶ —O—Si(CH₃)₂—O— 351 methyl methyl R⁸⁶ methyl methyl R⁸⁶—O—Si(CH₃)(Ph)—O— 352 methyl methyl R⁸⁶ methyl methyl R⁸⁶—O—Si(CH₃)₂—O—Si(CH₃)₂—O— 353 methyl methyl R⁸⁶ methyl methyl R⁸⁶—O—Si(CH₃)₂—O—Si(CH₃)₂—O—Si(CH₃)₂—O— 354 methyl —OSiMe₃ R⁸⁶ methyl—OSiMe₃ R⁸⁶ —O— 355 methyl phenyl R⁸⁶ methyl phenyl R⁸⁶ —O— 356 i-propyli-propyl R⁸⁶ i-propyl i-propyl R⁸⁶ —O— 357 cyclopentyl cyclopentyl R⁸⁶cyclopentyl cyclopentyl R⁸⁶ —O— 358 phenyl phenyl R⁸⁶ phenyl phenyl R⁸⁶—O— 359 phenyl R⁸⁶ R⁸⁶ phenyl R⁸⁶ R⁸⁶ —O— 360 R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶ R⁸⁶—O— In this table,

Further suitable compounds of the formula (XI) and/or (XI*) arespecified hereinafter. R therein is independently Me, phenyl or R⁸⁶,where at least one R radical is R⁸⁶:

In a very particularly preferred embodiment, the present inventionrelates to an OLED which, as well as at least one metal-carbene complexof the general formula (I), comprises at least one compound of thegeneral formula (X), in which case the compound of the formula (X) ismost preferably at least one of the compounds specified below:

In the aforementioned compounds, T is O or S, preferably O. When morethan one T occurs in the molecule, all T groups have the samedefinition.

In addition to the compounds of the formula (X), according to thepresent invention, it is also possible to use crosslinked or polymericmaterials comprising repeat units based on the general formula (X) incrosslinked or polymerized form together with at least one metal-carbenecomplex of the general formula (I). Like the compounds of the generalformula (X), the latter are preferably used as matrix materials.

The crosslinked or polymeric materials have outstanding solubility inorganic solvents, excellent film-forming properties and relatively highglass transition temperatures. In addition, high charge carriermobilities, high stabilities of color emission and long operating timesof the corresponding components can be observed when crosslinked orpolymeric materials according to the present invention are used inorganic light-emitting diodes (OLEDs).

The crosslinked or polymerized materials are particularly suitable ascoatings or in thin films since they are thermally and mechanicallystable and relatively defect-free.

The crosslinked or polymerized materials comprising repeat units basedon the general formula (X) can be prepared by a process comprising steps(a) and (b):

-   (a) preparation of a crosslinkable or polymerizable compound of the    general formula (X) where at least one of the a″ R⁵⁵ radicals or at    least one of the b′ R⁵⁶ radicals is a crosslinkable or polymerizable    group attached via a spacer, and-   (b) crosslinking or polymerization of the compound of the general    formula (X) obtained from step (a).

The crosslinked or polymerized materials may be homopolymers, whichmeans that exclusively units of the general formula (X) are present incrosslinked or polymerized form. They may also be copolymers, whichmeans that further monomers are present in addition to the units of thegeneral formula (X), for example monomers with hole-conducting and/orelectron-conducting properties, in crosslinked or polymerized form.

In a further preferred embodiment of the inventive OLED, it comprises anemission layer comprising at least one inventive metal-carbene complexof the general formula (I), at least one matrix material of the formula(X), and optionally at least one further hole-transporting matrixmaterial.

The inventive OLEDs can be used in all devices in whichelectroluminescence is useful. Suitable devices are preferably selectedfrom stationary and mobile visual display units and illumination means.The present invention therefore also relates to a device selected fromthe group consisting of stationary visual display units and mobilevisual display units and illumination means, comprising an inventiveOLED.

Stationary visual display units are, for example, visual display unitsof computers, televisions, visual display units in printers, kitchenappliances and advertising panels, illuminations and information panels.Mobile visual display units are, for example, visual display units incellphones, laptops, digital cameras, mp-3 players, smartphones,vehicles, and destination displays on buses and trains.

The inventive metal-carbene complexes of the general formula (I) canadditionally be used in OLEDs with inverse structure. In these inverseOLEDs, the inventive complexes are in turn preferably used in thelight-emitting layer. The structure of inverse OLEDs and the materialstypically used therein are known to those skilled in the art.

The present invention further provides a white OLED comprising at leastone inventive metal-carbene complex of the general formula (I). In apreferred embodiment, the metal-carbene complex of the general formula(I) is used as emitter material in the white OLED. Preferred embodimentsof the metal-carbene complex of the general formula (I) have beenspecified above. In addition to the at least one metal-carbene complexof the general formula (I), the white OLED may comprise

-   (i) at least one compound of the formula (X). The compound of the    formula (X) is preferably used as matrix material. Preferred    compounds of the formula (X) have been specified above; and/or-   (ii) at least one compound of the formula (VII) and/or (IX). The    compounds of the formula (VII) and/or (IX) are preferably used as    electron transport material. Preferred compounds of the    formulae (VII) and (IX) have been specified above.

In order to obtain white light, the OLED must generate light whichcolors the entire visible range of the spectrum. However, organicemitters normally emit only in a limited portion of the visiblespectrum—i.e. are colored. White light can be generated by thecombination of different emitters. Typically, red, green and blueemitters are combined. However, the prior art also discloses othermethods for formation of white OLEDs, for example the triplet harvestingapproach. Suitable structures for white OLEDs or methods for formationof white OLEDs are known to those skilled in the art.

In one embodiment of a white OLED, several dyes are layered one on topof another in the light-emitting layer of an OLED and hence combined(layered device). This can be achieved by mixing all dyes or by directseries connection of different-colored layers. The expression “layeredOLED” and suitable embodiments are known to those skilled in the art.

In general, the different layers then have the following thicknesses:anode (2) 500 to 5000 Å (ångström), preferably 1000 to 2000 Å;hole-transporting layer (3) 50 to 1000 Å, preferably 200 to 800 Å,either a light-emitting layer comprising a mixture of different emitters(4): 10 to 1000 Å, preferably 100 to 800 Å, or several light-emittinglayers in succession, each individual layer comprising a differentemitter (4a, b, c, . . . ): each 10 to 1000 Å, preferably each 50 to 600Å, electron-transporting layer (5) 50 to 1000 Å, preferably 200 to 800Å, cathode (6) 200 to 10 000 Å, preferably 300 to 5000 Å.

In a further embodiment of a white OLED, several different-colored OLEDsare stacked one on top of another (stacked device). For the stacking oftwo OLEDs, what is called a charge generation layer (CG layer) is used.This CG layer may be formed, for example, from one electrically n-dopedand one electrically p-doped transport layer. The expression “stackedOLED” and suitable embodiments are known to those skilled in the art.

In general, the different layers then have the following thicknesses:anode (2) 500 to 5000 Å (ångström), preferably 1000 to 2000 Å; firsthole-transporting layer (3) 50 to 1000 Å, preferably 200 to 800 Å, firstlight-emitting layer (4) 10 to 1000 Å, preferably 50 to 600 Å, firstelectron-transporting layer (5) 50 to 1000 Å, preferably 200 to 800 Å,electrically n-doped layer 50 to 1000 Å, preferably 100 to 800 Å,electrically p-doped layer 50 to 1000 Å, preferably 100 to 800 Å, secondhole-transporting layer (3) to 50 to 1000 Å, preferably 200 to 800 Å,second light-emitting layer (4) 10 to 1000 Å, preferably 50 to 600 Å,second electron-transporting layer (5) 50 to 1000 Å, preferably 200 to800 Å, electrically n-doped layer 50 to 1000 Å, preferably 100 to 800 Å,electrically p-doped layer 50 to 1000 Å, preferably 100 to 800 Å, thirdhole-transporting layer (3) to 1000 Å, preferably 200 to 800 Å, thirdlight-emitting layer (4) 10 to 1000 Å, preferably 50 to 600 Å, thirdelectron-transporting layer (5) to 50 to 1000 Å, preferably 200 to 800Å, cathode (6) 200 to 10 000 Å, preferably 300 to 5000 Å.

In further embodiments of this “stacked device concept”, it is alsopossible to stack only two OLEDs or to stack more than three OLEDs.

In a further embodiment of white OLEDs, the two concepts mentioned forwhite light generation can also be combined. For example, a single-colorOLED (for example blue) can be stacked with a multicolor layered OLED(for example red-green). Further combinations of the two concepts areconceivable and known to those skilled in the art.

The inventive metal-carbene complex of the formula (I) can be used inany of the layers mentioned above in white OLEDs. In a preferredembodiment, it is used in one or more or all light-emitting layer(s) ofthe OLED(s), in which case the structure of the invention metal-carbenecomplex is varied as a function of the use of the complex. Suitable andpreferred components for the further layers of the light OLED(s) ormaterials suitable as matrix material in the light-emitting layer(s) andpreferred matrix materials are likewise specified above.

The present invention also relates to an organic electronic component,preferably an organic light-emitting diode (OLED), organic photovoltaiccell (OPV), organic field-effect transistor (OFET) or light-emittingelectrochemical cell (LEEC), comprising at least one inventivemetal-carbene complex of the general formula (I).

EXAMPLES

The examples which follow, more particularly the methods, materials,conditions, process parameters, apparatus and the like detailed in theexamples, are intended to support the present invention, but not torestrict the scope of the present invention.

All experiments are carried out in protective gas atmosphere.

The percentages and ratios mentioned in the examples below—unless statedotherwise—are % by weight and weight ratios.

Example 1 2,3-Bis(N-phenylamino)pyrazine

A mixture of 2,3-dichloropyrazine (10.0 g, 67 mmol) in aniline (35.3 ml,376 mmol) is stirred at 105° C. overnight. After cooling to 80° C.,water (100 ml) is added. The mixture is adjusted to pH 11 with 50%sodium hydroxide solution and extracted with dichloromethane and ethylacetate. The combined organic phases are concentrated to dryness and thecrude product is purified by column chromatography (silica gel,n-hexane/ethyl acetate 4:1). Yield: 16.2 g (92%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=6.27 (br s, 2H), 7.00 (m_(c), 2H), 7.26-7.30(m, 8H), 7.72 (s, 2H).

1,3-Diphenylpyrazinoimidazolium iodide

A mixture of 2,3-bis(N-phenylamino)pyrazine (15.5 g, 59 mmol) intriethyl orthoformate (100 ml) is admixed with ammonium iodide (17.1 g,118 mmol) and stirred overnight at 80° C. After cooling to roomtemperature, the solid is filtered off with suction, washed withpetroleum ether and dried in a vacuum drying cabinet at 70° C. Yield:19.5 g (82%).

¹H NMR (d₆-DMSO, 500 MHz): δ=7.77 (m_(c), 2H), 7.84 (m_(c), 4H),8.03-8.08 (m, 4H), 9.08 (s, 2H), 11.20 (s, 1H).

Complex fac-Em1:

A suspension of 1,3-diphenylpyrazinoimidazolium iodide (1.6 g, 4.0 mmol)in dioxane (95 ml) is admixed with molecular sieve (14 g) and silver(I)oxide (742 mg, 3.2 mmol) and stirred overnight at room temperature.Subsequently, a solution of chloro(1,5-cyclooctadiene)indium(I) dimer(269 mg, 0.4 mmol) in o-xylene (130 ml) is added. The mixture is stirredat reflux overnight. After cooling to 80° C., the residue is filteredoff with suction and washed with o-xylene. The combined filtrates areconcentrated to dryness and the residue is dissolved at 75° C. intoluene (40 ml). The solution is concentrated and left to standovernight at room temperature. The precipitate is filtered off, washedwith cyclohexane and dried in a vacuum drying cabinet at 65° C. Yield:0.8 g (95%).

¹H NMR (d₆-DMSO, 500 MHz, 100° C.): δ=6.51-6.59 (m, 9H), 6.70 (m_(c),3H), 6.81 (m_(c), 3H), 6.90 (br m, 6H), 7.09 (m_(c), 3H), 8.16 (d, 3H),8.42 (d, 3H), 8.66 (dd, 3H).

Photoluminescence (2% in a PMMA film):

λ_(max)=474 nm, CIE: (0.16; 0.24), QY=93%

Example 2 2-N-Isopropylamino-3-chloropyrazine

A solution of 2-amino-3-chloropyrazine (2.7 g, 20.8 mmol) indichloromethane (54 ml) and glacial acetic acid (27 ml) is admixed at 1°C. with acetone (4.1 ml, 56.3 mmol) and borane-dimethyl sulfide complex(2.2 ml, 22.9 mmol) and stirred overnight at room temperature. A secondportion of borane-dimethyl sulfide complex (0.8 ml) is added at 1° C.and the mixture is again stirred overnight at room temperature. Finally,a third portion of borane-dimethyl sulfide complex (0.6 ml) and acetone(1.0 ml) is added at 1° C. and the mixture is again stirred overnight atroom temperature. The solution is adjusted to pH 9 at <10° C. withaqueous ammonia (38 ml). The organic phase is removed and washed withwater. After drying over sodium sulfate, the solution is concentratedand left to stand overnight. The precipitate which forms is filtered offand washed with a little dichloromethane. The combined filtrates areconcentrated to dryness and dried in a vacuum drying cabinet at 40° C.Yield: 2.3 g (64%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=1.22 (d, 6H), 4.16 (sept, 1H), 5.00 (br s,1H), 7.46 (d, 1H), 7.88 (d, 1H).

2-N-Phenylamino-3-N-isopropylaminopyrazine

A mixture of 2-isopropylamino-3-chloropyrazine (5.1 g, 30 mmol) inaniline (9 ml, 99 mmol) is stirred overnight at 125° C. After cooling to90° C., water is added. At room temperature, dichloromethane is addedand the solution is adjusted to pH 9 with aqueous ammonia. The organicphase is removed, washed with water, dried over sodium sulfate andconcentrated to dryness. The crude product is purified by columnchromatography (silica gel, toluene/ethyl acetate 8:1). Yield: 4.6 g(68%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=1.23 (d, 6H), 4.15 (br s, 1H), 4.18 (sept,1H), 5.95 (br s, 1H), 6.96-7.02 (m, 1H), 7.23-7.32 (m, 4H), 7.45 (d,1H), 7.64 (d, 1H).

1-Phenyl-3-isopropylpyrazinoimidazolium iodide

A mixture of 2-N-phenylamino-3-N-isopropylaminopyrazine (1.2 g, 5.2mmol) in triethyl orthoformate (6 ml) is admixed with ammonium iodide(0.8 g, 5.7 mmol) and stirred overnight at 80° C. After cooling to roomtemperature, the solid is filtered off with suction, washed with alittle ethanol and petroleum ether, and dried in a vacuum drying cabinetat 50° C. Yield: 1.1 g (60%).

¹H NMR (d₆-DMSO, 500 MHz): δ=1.76 (d, 6H), 5.23 (sept, 1H), 7.67-7.84(m, 3H), 7.91-8.02 (m, 2H), 8.98 (d, 1H), 9.02 (d, 1H), 10.72 (s, 1H).

Complex mer-Em2

A suspension of 1-phenyl-3-isopropylpyrazinoimidazolium iodide (166 mg,0.48 mmol) in dioxane (8 ml) is admixed with molecular sieve (1 g) andsilver(I) oxide (89 mg, 0.38 mmol) and stirred overnight at roomtemperature. Chloro(1,5-cyclooctadiene)-iridium(I) dimer (30 mg, 0.05mmol) is added and the mixture is stirred overnight at reflux. Aftercooling to room temperature, the residue is filtered off with suctionand washed with dichloromethane. The combined filtrates are concentratedto dryness and the residue is purified by column chromatography (silicagel, toluene/ethyl acetate 4:1). Yield: 65 mg (80%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=0.72 (d, 3H), 0.77 (d, 3H), 0.87 (d, 3H),1.36 (d, 3H), 1.45 (d, 3H), 1.77 (d, 3H), 4.37-4.53 (m, 2H), 4.65 (sept,1H), 6.57 (dd, 1H), 6.65-6.74 (m, 3H), 6.94-7.24 (m, 5H), 8.17 (d, 1H),8.22 (d, 1H), 8.23 (d, 1H), 8.28 (d, 1H), 8.30 (d, 1H), 8.33 (d, 1H),8.60 (dd, 1H), 8.63 (dd, 1H), 8.67 (dd, 1H).

Photoluminescence (2% in a PMMA film):

λ_(max)=516 nm, CIE: (0.29; 0.51), QY=66%

Complex fac-Em2

A solution of mer-Em2 (720 mg, 0.80 mmol) in butanone (70 ml) is admixedwith hydrochloric acid (1 N, 10 ml) and stirred under reflux overnight.The solution is concentrated, diluted with dichloromethane and washedwith water. The organic phase is dried over sodium sulfate andconcentrated to dryness. The residue is purified by columnchromatography (silica gel, toluene/ethyl acetate 10:1). Yield: 327 mg(45%).

¹H NMR (CD₂Cl₂, 500 MHz, 100° C.): δ=0.86 (d, 9H), 1.70 (d, 9H), 4.54(sept, 3H), 6.36 (d, 3H), 6.64 (dd, 3H), 7.02 (dd, 3H), 8.17 (d, 3H),8.28 (d, 3H), 8.60 (d, 3H).

Photoluminescence (2% in a PMMA film):

λ_(max)=474 nm, CIE: (0.16; 0.27), QY=90%

Example 3 2-N-Phenylamino-3-aminopyrazine

A mixture of 2-amino-3-chloropyrazine (5.0 g, 39 mmol) in aniline (12ml, 131 mmol) is twice stirred overnight at 100° C. After cooling toroom temperature, the mixture is diluted with dichloromethane (80 ml),stirred overnight and filtered. The solid is dissolved indichloromethane (200 ml) and washed with saturated aqueous sodiumhydrogencarbonate solution. The organic phase is concentrated to drynessand the residue is dried in a vacuum drying cabinet at 70° C. Yield: 5.3g (74%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=4.43 (br s, 2H), 6.23 (br s, 1H), 7.03 (dd,1H), 7.32 (dd, 2H), 7.40 (d, 2H), 7.59 (d, 1H), 7.62 (d, 1H).

1-Phenylpyrazinoimidazole

A solution of 2-N-phenylamino-3-aminopyrazine (5.3 g, 29 mmol) in formicacid (160 ml) is stirred overnight under reflux and then concentrated todryness. The residue is taken up in dichloromethane (100 ml) and washedwith saturated aqueous sodium hydrogencarbonate solution. The aqueousphase is extracted with dichloromethane (2×50 ml) and the combinedorganic phases are concentrated to dryness. Yield: 5.6 g (98%)

¹H NMR (CD₂Cl₂, 500 MHz): δ=7.49 (dd, 1H), 7.60 (dd, 2H), 7.76 (d, 2H),8.39 (d, 1H), 8.56 (d, 1H), 8.63 (s, 1H).

1-Phenyl-3-methylpyrazinoimidazolium tetrafluoroborate

A solution of 1-phenylpyrazinoimidazole (5.5 g, 28 mmol) indichloromethane (400 ml) is admixed with trimethyloxoniumtetrafluoroborate (4.2 g, 28 mmol) and stirred overnight at reflux. Theprecipitate is filtered off and dried. The product is obtained in apurity of approx. 75%. Yield: 7.3 g (87%).

¹H NMR (d₆-DMSO, 500 MHz): δ=4.19 (s, 3H), 7.71 (dd, 1H), 7.78 (dd, 2H),7.91 (d, 2H), 8.99 (d, 1H), 9.04 (d, 1H), 10.70 (s, 1H).

1-Phenyl-3-methylpyrazinoimidazolium iodide

A solution of 1-phenyl-3-methylpyrazinoimidazolium tetrafluoroborate(7.3 g, 25 mmol, purity: 75%) in acetonitrile (70 ml) is admixed with asolution of tetrabutylammonium iodide (27.2 g, 74 mmol) in acetonitrile(67 ml) and stirred overnight at room temperature. The precipitate isfiltered off with suction and washed with petroleum ether. The productis obtained in a purity of approx. 75%. Yield: 6.0 g (72%).

¹H NMR (d₆-DMSO, 500 MHz): δ=4.19 (s, 3H), 7.71 (dd, 1H), 7.78 (dd, 2H),7.92 (d, 2H), 8.99 (d, 1H), 9.04 (d, 1H), 10.72 (s, 1H).

Complex mer-Em3

A suspension of 1-phenyl-3-methylpyrazinoimidazolium iodide (1.0 g, 2.3mmol) in dioxane (60 ml) is admixed with molecular sieve (8.4 g) andsilver(I) oxide (0.4 g, 1.8 mmol) and stirred overnight at roomtemperature. A solution of chloro(1,5-cyclooctadiene)iridium(I) dimer(153 mg, 0.2 mmol) in o-xylene (83 ml) is added and the mixture isstirred overnight at reflux. After cooling to room temperature, theresidue is filtered off with suction and washed with acetone. Thecombined filtrates are concentrated to dryness and the residue ispurified by column chromatography (silica gel, dichloromethane). Yield:44 mg (13%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=3.22 (s, 3H), 3.36 (s, 3H), 3.37 (s, 3H),6.60 (dd, 1H), 6.70-6.78 (m, 3H), 6.87 (dd, 1H), 6.92 (dd, 1H),7.01-7.10 (m, 3H), 8.22 (d, 1H), 8.27 (d, 1H), 8.28 (d, 1H), 8.32 (d,1H), 8.35 (d, 1H), 8.36 (d, 1H), 8.60 (dd, 1H), 8.67 (dd, 1H), 8.68 (dd,1H).

Photoluminescence (2% in a PMMA film):

λ_(max)=515 nm, CIE: (0.29; 0.50), QY=74%

Complex fac-Em3

A solution of mer-Em3 in butanone is admixed with hydrochloric acid andstirred overnight under reflux. The solution is concentrated, dilutedwith dichloromethane and washed with water. The organic phase is driedover sodium sulfate and concentrated to dryness. The residue is purifiedby column chromatography.

Example 4 μ-Dichloro Dimer D1

N-(2,6-Diisopropylphenyl)-2-phenylimidazole is synthesized analogouslyto example 14 in WO2006/121811.

3.50 g (11.5 mmol) of 1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazoleare initially charged in 200 ml of 2-ethoxyethanol/water (ratio 3/1) andadmixed with 1.84 g (5.2 mmol) of iridium(III) chloride trihydrate. Thereaction mixture is heated at reflux for 18 h. After cooling, 50 ml ofdistilled water are added. The precipitate is filtered off, washed withdistilled water and dried. This gives 3.50 g (80%) of □-dichloro dimerD1 as a yellow powder.

¹H NMR (CD₂Cl₂, 400 MHz):

δ=0.95 (d, 12H), 1.18 (d, 12H), 1.27 (d, 12H), 1.34 (d, 12H), 2.80-2.91(m, 8H), 6.08 (d, 4H), 6.24 (d, 4H), 6.39 (pt, 4H), 6.53 (pt, 4H), 6.97(d, 4H), 7.39-7.45 (m, 8H), 7.59 (t, 4H), 7.67 (d, 4H).

Complex mer-Em7

A suspension of 1,3-diphenylpyrazinoimidazolium iodide (0.5 g, 1.25mmol) in anhydrous dioxane (100 ml) is admixed with molecular sieve (10g) and silver(I) oxide (0.19 g, 0.81 mmol) and stirred overnight at roomtemperature. Subsequently, a solution of chloro dimer D1 (0.52 g, 0.31mmol) in dioxane (74 ml) is added dropwise. Thereafter, the mixture isstirred under reflux for one hour. The reaction mixture is cooled andfiltered. The filtrate is freed of the solvent under reduced pressure,washed with methanol and then purified by column chromatography (silicagel, eluent cyclohexane/acetone=1/0.25). This gives 0.40 g of mer-Em7 asan orange powder (63%).

¹H NMR (CD₂Cl₂, 500 MHz):

δ=0.89 (d, 3H), 0.90 (d, 6H), 0.92 (d, 3H), 1.09 (d, 3H), 1.16 (d, 3H),1.21 (d, 3H), 1.24 (d, 3H), 2.13 (sept, 1H), 2.66 (m, 2H), 2.73 (sept,1H), 6.08-6.23 (m, 5H), 6.45-6.48 (m, 3H), 6.66 (d, 1H), 6.70-6.76 (m,3H), 6.85-6.92 (m, 2H), 6.98 (m, 4H), 7.08-7.13 (m, 2H), 7.31 (t, 2H),7.35 (d, 1H), 7.39 (d, 1H), 7.50 (t, 1H), 7.55 (t, 1H), 8.21 (d, 1H),8.41 (d, 1H), 8.80 (d, 1H).

Photoluminescence (2% in a PMMA film):

λ_(max)=565 nm, CIE: (0.44; 0.49)

Complex fac-Em7

The complex fac-Em7 (isomer to mer-Em7) is obtained by irradiation of asolution of mer-Em7 in 3-methoxypropionitrile with a blacklight bluelamp (Osram, L18W/73, λ_(max)=370-380 nm) and subsequent purification bycolumn chromatography.

Example 5 Complex K1

5.00 g (14.0 mmol) of benzimidazolium salt S1 are suspended in 80 ml ofanhydrous toluene and cooled to −8° C. Then 28 ml of potassiumbis(trimethylsilyl)amide (KHMDS, 0.5M in toluene, 14.0 mmol) are addedwithin 10 min. The mixture is stirred at room temperature for one hourand then added dropwise at −78° C. within 15 min to a solution of 4.70 g(7.0 mmol) of [(μ-Cl)Ir(η⁴-1,5-COD)]₂ in 120 ml toluene. The reactionmixture is stirred at room temperature for 1.5 h and then heated atreflux for 19 h. After cooling, the precipitate is filtered off andwashed with toluene. The combined toluene phases are concentrated todryness and purified by column chromatography (silica gel, eluentmethylene chloride). This gives 5.8 g (68%) of K1 as a yellow powder.

¹H NMR (CD₂Cl₂, 500 MHz):

δ=1.17 (m, 2H), 1.34 (m, 4H), 1.61 (m, 2H), 2.43 (m, 2H), 4.31 (m, 2H),7.18 (m, 2H), 7.25 (m, 2H), 7.51 (m, 6H), 7.96 (m, 4H).

Complex Em8

A suspension of 1,3-diphenylpyrazinoimidazolium iodide (3.17 g, 7.92mmol) in anhydrous 1,4-dioxane (140 ml) is admixed with molecular sieve(15 g) and silver(I) oxide (1.48 g, 6.34 mmol) and stirred overnight atroom temperature. Subsequently, a solution of complex K1 (1.60 g, 2.64mmol) in anhydrous o-xylene (200 ml) is added dropwise. Thereafter, themixture is stirred under reflux for 24 hours. The reaction mixture iscooled and filtered. The filtrate is freed of the solvent under reducedpressure and purified by column chromatography (silica gel, eluent ethylacetate/cyclohexane=1/2). This gives 0.80 g of Em8 (30%).

¹H NMR (CD₂Cl₂, 500 MHz):

δ=6.20-7.40 (very flat broad signal, 8H), 6.26 (d, 1H), 6.36-6.42 (m,3H), 6.59 (d, 1H), 6.66 (t, 2H), 6.76-6.85 (m, 6H), 7.06-7.17 (m, 4H),7.29 (t, 1H), 7.33 (t, 1H), 8.01 (m, 2H), 8.04 (d, 1H), 8.18 (d, 1H),8.27 (d, 1H), 8.31 (d, 1H), 8.70 (d, 1H), 8.77 (d, 1H).

Photoluminescence (2% in a PMMA film):

λ_(max)=480 nm, CIE: (0.17; 0.31)

Example 6 Complex D2

4.29 g (18.5 mmol) of silver oxide, 9.47 g (33.1 mmol) of imidazoliumiodide and 3.56 g (10.1 mmol) of iridium trichloride trihydrate aresuspended in 350 ml of 2-ethoxyethanol and stirred in the dark at 120°C. for 15 h. Thereafter, the solvent is removed under reduced pressureand the residue is extracted with methylene chloride. The extract isconcentrated to about a quarter of its volume and admixed with methanol.The solid which precipitates out is filtered off and dried. This gives1.7 g of complex D2 (31%).

¹H NMR (CD₂Cl₂, 500 MHz):

δ=7.59 (d, 4H), 7.17 (d, 4H), 6.99 (d, 4H), 6.73 (pt, 4H), 6.45 (pt,4H), 6.09 (d, 4H), 3.91 (s, 12H).

Complex Em9

A suspension of 1,3-diphenylpyrazinoimidazolium iodide (0.59 g, 1.48mmol) in anhydrous 1,4-dioxane (35 ml) is admixed with molecular sieve(5 g) and silver(I) oxide (0.28 g, 1.18 mmol) and stirred overnight atroom temperature. Subsequently, a suspension of complex D2 (0.40 g, 0.37mmol) in anhydrous o-xylene (50 ml) is added. Thereafter, the mixture isstirred under reflux for 3.5 hours. The reaction mixture is cooled andfiltered. The filtrate is freed of the solvent under reduced pressureand purified by column chromatography (silica gel, eluentdichloromethane).

This gives a fraction 1 of 0.11 g (20%, orange powder, R_(F)=0.39, 20/80isomer mixture) and a fraction 2 of 0.23 g (40%, yellow powder,R_(E)=0.31, 40/60 isomer mixture) as mixtures of two different isomerseach of Em9.

Fraction 1:

MS (Maldi):

m/e=779 (M+H⁺)

Photoluminescence (2% in a PMMA film):

λ_(max)=547 nm, CIE: (0.40; 0.54)

Fraction 2:

MS (Maldi):

m/e=779 (M+H⁺)

Photoluminescence (2% in a PMMA film):

λ_(max)=526 nm, CIE: (0.33; 0.55)

Example 7 Complex K2

3.10 g (9.41 mmol) of5-methoxy-1,3,4-triphenyl-4,5-dihydro-1H-[1,2,4]-triazole are heated to90° C. under reduced pressure (10⁻³ mbar) for 16 h. After cooling, theresidue is taken up in 120 ml of anhydrous toluene and admixed with asolution of 1.38 g (2.03 mmol) of p-chloro(1,5-cyclooctadiene)iridium(I)dimer in 120 ml of anhydrous toluene. The reaction mixture is heatedgradually to 50° C. and stirred at this temperature for 1 h. Aftercooling, the orange-red precipitate is filtered off, washed with tolueneand dried. This gives 2.68 g of K2 (70%).

¹H NMR (CD₂Cl₂, 500 MHz):

δ=1.19 (m, 2H), 1.29 (m, 2H), 2.14 (m, 2H), 2.26 (m, 2H), 2.77 (m, 2H),4.95 (m, 2H), 7.25-7.44 (m, 26H), 7.82 (d, 4H).

Complex Em10

A suspension of 0.5 g (1.25 mmol) of 1,3-diphenylpyrazinoimidazoliumiodide in dry dioxane (40 ml) is admixed with 10 g of molecular sieveand 0.22 g (0.95 mmol) of silver(I) oxide and stirred overnight at roomtemperature. Subsequently, 0.94 g (1.01 mmol) of complex K2 is added inportions. The reaction mixture is heated under reflux overnight. Aftercooling, the precipitate is filtered off. The filtrate is concentratedto dryness, purified by column chromatography (silica gel, eluent:cyclohexane/acetone) and washed with a little methanol. This gives 0.21g of emitter Em10 (20%).

Example 8 Complex K3

10.4 g (27.6 mmol) of 3-dibenzofuran-4-yl-1-methyl-3H-imidazol-1-iumiodide in 230 ml of anhydrous toluene are admixed at room temperaturegradually with 55.3 ml of potassium bis(trimethylsilyl)amide solution(KHMDS, 0.5M in toluene, 27.6 mmol) and stirred for one hour.Subsequently, a solution of 4.68 g (6.9 mmol) ofp-chloro(1,5-cyclooctadiene)iridium(I) dimer in 230 ml of anhydroustoluene is added dropwise. The reaction mixture is heated at refluxovernight. After cooling, the precipitate is filtered off, washed with alittle water and extracted with ethanol. Drying the extract gives 6.8 gof K3 (53%) as an orange-red powder.

¹H NMR (CD₂Cl₂, 500 MHz):

δ=1.49 (m, 2H), 1.84 (m, 2H), 2.02 (m, 2H), 2.16 (m, 2H), 3.29 (m, 2H),4.85 (m, 2H), 6.53 (s, 2H), 6.93 (s, 2H), 7.37 (d, 2H), 7.47-7.62 (m,8H), 8.14 (d, 2H), 8.25 (d, 2H).

Complex Em11

Em11 is synthesized analogously to Em10.

Example 9 Production of an OLED Comparison of Different Emitters

The ITO substrate used as the anode is cleaned first with commercialdetergents for LCD production (Deconex® 20NS, and 25ORGAN-ACID®neutralizing agent) and then in an acetone/isopropanol mixture in anultrasound bath. To eliminate possible organic residues, the substrateis exposed to a continuous ozone flow in an ozone oven for a further 25minutes. This treatment also improves the hole injection properties ofthe ITO. Next, the hole injection layer AJ20-1000 from Plexcore is spunon from solution.

Thereafter, the organic materials specified below are applied by vapordeposition to the cleaned substrate at about 10⁻⁷-10⁻⁹ mbar at a rate ofapprox. 0.5-5 nm/min. The hole conductor and exciton blocker applied tothe substrate is Ir(DPBIC)₃ with a thickness of 45 nm, of which thefirst 35 nm are doped with MoO_(x) (10% for diodes with CEm and fac-Em2,50% for diodes with fac-Em1) to improve the conductivity.

(for preparation of Ir(DPBIC)₃ see Ir complex (7) in the applicationPCT/EP/04/09269).

Subsequently, a mixture of emitter (10% for CEm, 20% for fac-Em1 andfac-Em2) and of the compound Ma1 (90% and 80%, resp.) is applied byvapor deposition with a thickness of 40 nm, the latter compoundfunctioning as a matrix material. Subsequently, the material Ma1 (forfac-Em1) is applied by vapor deposition with a thickness of 5 nm or Ma5(5 nm for Em1, 10 nm for fac-Em2) as an exciton and hole blocker.

The synthesis of Ma1 is described in WO2010079051, that of Ma5 inWO2009003898.

The prior art comparative emitter used is CEm:

Next, as an electron transporter, a mixture of Liq and BCP(2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) (50:50 for fac-Em1,0:100 for CEm and fac-Em2) is applied by vapor deposition in a thicknessof 40 nm for fac-Em1, 30 nm for CEm and fac-Em2, as are a 1.0 nm-thickliq layer for fac-Em1, a 0.7 nm LiF layer for CEm and fac-Em2 andfinally a 100 nm-thick Al electrode. All components are adhesive-bondedto a glass lid in an inert nitrogen atmosphere.

To characterize the OLED, electroluminescence spectra are recorded atdifferent currents and voltages. In addition, the current-voltagecharacteristic is measured in combination with the light output emitted.The light output can be converted to photometric parameters bycalibration with a photometer. The lifetime t_(1/2) of the diode isdefined by the time taken for the luminance to fall to 50% of itsinitial value. The lifetime measurement is carried out at a constantcurrent.

For the different emitters in the above-described OLED structure, thefollowing electrooptical data are obtained:

lm/W t_(1/2) @ 300 nits (normalized to the Emitter CIE @ 300 nits valueof CEm) CEm 0.15, 0.15 6.5 100% fac-Em2 0.17, 0.30 6.4 714% fac-Em10.17, 0.28 4.5 5300%

Example 10 Influence of the Matrix Material (Part 1)

The emission layer of the structure described in example 9 is varied.The doping level of MoO_(x) is 50%. A mixture of emitter fac-Em1 (20%)and different matrix materials (80%) is applied by vapor deposition witha thickness of 20 nm. The hole/exciton blocker (5 nm) used in each caseis the matrix material. The electron conductor used is a mixture of BCPand liq (50:50) in a thickness of 40 nm. The electron injector used isliq (1 nm). In addition to Ma1, the following materials are used:

The syntheses of Ma2, Ma3 and Ma4 are described in WO2010079051.

Ma6 can be prepared by a process known to a person skilled in the art.9-(8-Bromo-dibenzofuran-2-yl)-9H-carbazole (see WO2010079051) is reactedwith n-BuLi in THF and2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane to give9-[8-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)dibenzofuran-2-yl]-9H-carbazole(analogously to stage 1 of Example 18), which is then reacted in aSuzuki coupling known to those skilled in the art with 1,3-diiodbenzeneto give Ma6.

The synthesis of Ma7 is described in Example 19.

For the different matrix materials in the above-described OLEDstructure, the following electrooptical data are obtained (normalized tothe value of Ma5):

EQE lm/W Matrix CIE @ 300 nits @ 300 nits Voltage @ 300 nitsMa2^(a,b,c,d,e) 0.17, 0.28 98% 120% 95% Ma3^(f) 0.17, 0.28 106% 160% 77%Ma1 0.17, 0.26 119% 164% 80% Ma4^(f,g) 0.17, 0.28 109% 176% 72% Ma50.16, 0.23 100% 100% 100% Ma6^(a) 0.17, 0.29 120% 171% 83% Ma7^(a,f,h)0.17, 0.31 133% 275% 60% ^(a)10% MoO_(x) doping ^(b)Emission layer 40 nm^(c)Ma1 as hole/exciton blocker 10 nm ^(d)Electron conductor: 20 nmBCP:Ma1 80:20 ^(e)Electron injector: LiF (0.7 nm) ^(f)Doping level 30%emitter in 70% matrix ^(g)Electron conductor layer 35 nm^(h)Hole/exciton blocker 10 nm, electron conductor 20 nm, electroninjector CsF

Example 10a

The emission layer of the structure described in Example 10 is varied.The emission layer used is a mixture of fac-Em1 (30%) and matrix (seetable below, 70%). The hole conductor layer used is a layer of 40 nm ofIr(DPBIC)₃, of which the first 35 nm have been doped with ReO₃ (5%). Thehole/exciton blocker used is a layer of 5 nm of Ma7. The electronconductor used is a mixture of liq and ETM1 (50:50, 40 nm). The electroninjector used is KF in a thickness of 4 nm.

ETM1 is commercially available.

The syntheses of Ma8, Ma9 and Ma10 are described in JP2006083167.

For the different matrix materials in the above-described OLEDstructure, the following electrooptical data are obtained (normalized tothe value of Ma8):

EQE Matrix CIE @ 300 nits Ma8 0.18, 0.31 100% Ma9 0.17, 0.30 145% Ma100.17, 0.31 128% Ma7* 0.16, 0.26 154% *Doping level emitter 10%

Example 10b

A diode with the emitter Em8 is constructed analogously to Example 10.The hole conductor layer is 40 nm thick. Em8 is doped at a level of 30%into Ma4. The electron conductor layer used is ETM1 in a thickness of 40nm. The electron injector used is KF (2 nm).

The diode exhibits the color coordinates CIE 0.19, 0.37. At 300 cd/m²,the voltage is 3.5 V and the luminous efficiency is 11 Im/W.

Example 10c

A diode is constructed analogously to Example 10a for Ma7. The emitterused is Em8 instead of fac-Em1.

The diode exhibits the color coordinates CIE 0.17, 0.31.

Example 10d

A diode is constructed analogously to Example 10a for Ma7. The emitterused is Em8 instead of fac-Em1. The matrix is varied. For the differentmatrix materials in the above-described OLED structure, the followingelectrooptical data are obtained (normalized to the value of Ma10):

EQE lm/W Matrix CIE @ 300 nits @ 300 nits Voltage @ 300 nits Ma10 0.17,0.32 100% 100% 100% Ma8 0.17, 0.30 128% 133% 94% Ma9 0.17, 0.30 149%156% 92%

Example 10e

A diode is constructed analogously to Example 10a. The emitter used isfac-Em12 instead of fac-Em1 in a dopant concentration of 20% in thematrix Ma4 (80%). The hole/exciton blocker is used in a thickness of 10nm.

The diode exhibits the color coordinates CIE 0.19, 0.36. At 300 cd/m²the voltage is 4.0 V and the external quantum efficiency 13%.

Example 10f

A diode is constructed analogously to Example 10a. The emitter used isfac-Em14 instead of fac-Em1 in a dopant concentration of 20% in thematrix Ma4 (80%). The hole/exciton blocker is used in a thickness of 10nm.

The diode exhibits the color coordinates CIE 0.20, 0.27.

Example 10g

A diode is constructed analogously to Example 10a. The hole conductorand exciton blocker applied to the substrate is Ir(DPBIC)₃ with athickness of 45 nm, of which the first 35 nm have been doped withMoO_(x) (10%) to improve the conductivity. The hole/exciton blocker isapplied in a thickness of 10 nm. The emitter used is fac-Em13 instead offac-Em1 in a dopant concentration of 20% in the matrix Ma4 (80%).

The diode exhibits the color coordinates CIE 0.14, 0.22. At 300 cd/m²,the voltage is 3.7 V.

Example 10h

A diode is constructed analogously to Example 10g. The emitter used isfac-Em13 in a dopant concentration of 20% in the matrix Ma7 (80%).

The diode exhibits the color coordinates CIE 0.14, 0.22. At 300 cd/m²the voltage is 3.6 V and the external quantum efficiency 16%.

Example 11 Influence of the Matrix Material (Part 2)

The emission layer of the structure described in example 10 is varied. Amixture of emitter fac-Em1 (20%) and one or two matrix materials isapplied by vapor deposition with a thickness of 20 nm. When two matrixmaterials are used, the two matrix materials are used in equal ratios.The hole/exciton blocker used in each case is Ma1.

The following electrooptical data are obtained:

Voltage @ 300 nits (normalized to Matrix CIE the value of Ma1) Ma1 0.17,0.26 100% Ir(DPBIC)₃ 0.16, 0.24  83% Ma1 +Ir(DPBIC)₃ 0.16, 0.23  77%Ma11 0.17, 0.29  93% Ma11 +Ir(DPBIC)₃ 0.16, 0.25  73%

Ma11 is commercially available.

Example 11a

Construction as in Example 10a. The emission layer used is a mixture ofIr(DPBIC)₃ (35%), fac-Em1 (30%) and matrix (35%, see table below). Thehole/exciton blocker used in each case is the matrix material.

The synthesis of Ma13 is described in WO2009008100.

The synthesis of Ma12 is described in Example 20 and the synthesis ofMa14 is described in Example 18.

For the different matrix materials in the above-described OLEDstructure, the following electrooptical data are obtained (normalized tothe value of Ma9):

EQE lm/W Matrix CIE @ 300 nits @ 300 nits Voltage @ 300 nits Ma9* 0.18,0.32 100% 100% 100% Ma7 0.18, 0.33 105% 112% 97% Ma4 0.17, 0.32 102%107% 94% Ma12a 0.17, 0.30 117% 124% 91% Ma13 0.17, 0.31 116% 107% 106%Ma14 0.17, 0.31 104% 121% 86% *The hole/exciton blocker used is Ma7^(a)Electron injection layer 2 nm

Example 11b

Construction as in Example 10a. The emission layer used is a mixture ofIr(DPBIC)₃ (45%), Em8 (10%) and matrix (45%, see table below).

For the different matrix materials in the OLED structure describedabove, the following electrooptical data are obtained (normalized to thevalue of Ma9):

EQE lm/W Matrix CIE @ 300 nits @ 300 nits Voltage @ 300 nits Ma9* 0.17,0.31 100% 100% 100% Ma4 0.17, 0.34 107% 131% 87% Ma7 0.17, 0.35 106%129% 87% Ma13^(a) 0.17, 0.32 93% 118% 79% *The hole/exciton blocker usedis Ma7 ^(a)The electron injector used is CsF (4 nm)

Example 11c

Construction as in Example 11a. The hole conductor and exciton blockerapplied to the substrate is Ir(DPBIC)₃ with a thickness of 40 nm, ofwhich the first 35 nm have been doped with MoO_(x) (50%) to improve theconductivity. The emission layer used is a mixture of Ir(DPBIC)₃ (40%),fac-Em12 (20%) and Ma4 (40%). The electron conductor layer used is amixture of ETM1:Liq (75:25) in a thickness of 40 nm. The electroninjector used is KF (2 nm).

The diode exhibits the color coordinates CIE 0.20, 0.40. At 300 cd/m²,the voltage is 3.0 V and the external quantum efficiency 13%.

Example 11d

Structure as in Example 11b. The emission layer used is a mixture ofIr(DPBIC)₃ (45%), fac-Em14 (10%) and Ma4 (45%).

The diode exhibits the color coordinates CIE 0.26, 0.39. At 300 cd/m²,the voltage is 3.0 V.

Example 11e

A diode is constructed analogously to Example 11a. The hole conductorand exciton blocker applied to the substrate is Ir(DPBIC)₃ with athickness of 45 nm, of which the first 35 nm have been doped withMoO_(x) (10%) to improve the conductivity. The hole/exciton blocker usedis Ma7 (5 nm). The emission layer used is a mixture of Ir(DPBIC)₃ (40%),fac-Em13 (30%) and Ma4 (30%).

The diode exhibits the color coordinates CIE 0.15, 0.26. At 300 cd/m²,the voltage is 3.4 V.

Example 11f

A diode is constructed analogously to Example 11a. The hole conductorand exciton blocker applied to the substrate is Ir(DPBIC)₃ with athickness of 45 nm, of which the first 35 nm have been doped withMoO_(x) (10%) to improve the conductivity. The hole/exciton blocker isapplied in a thickness of 10 nm. The emission layer used is a mixture ofIr(DPBIC)₃ (40%), fac-Em13 (30%) and Ma7 (30%).

The diode exhibits the color coordinates CIE 0.14, 0.25. At 300 cd/m²,the external quantum efficiency is 15%.

Example 11g

A diode is constructed analogously to Example 11a. The emission layerused is a mixture of Ir(DPBIC)₃(40%), fac-Em13 (30%) and Ma15 (30%).

The diode exhibits the color coordinates CIE 0.14, 0.23. At 300 cd/m²,the external quantum efficiency is 17%.

Synthesis of Ma15 is described in WO2010079051.

Example 11h

A diode is constructed analogously to Example 11a for Ma12. Instead ofMa12, Ma16 (see synthesis in JP2009267255) is used.

The diode exhibits the color coordinates CIE 0.18, 0.34 and a voltage of3.3 V at 300 cd/m².

Example 11i White Diodes

The ITO substrate used as the anode is cleaned first with commercialdetergents for LCD production (Deconex® 20NS, and 25ORGAN-ACID®neutralizing agent) and then in an acetone/isopropanol mixture in anultrasound bath. To eliminate possible organic residues, the substrateis exposed to a continuous ozone flow in an ozone oven for a further 25minutes. This treatment also improves the hole injection properties ofthe ITO. Next, the hole injection layer AJ20-1000 from Plexcore is spunon from solution.

Layered White (Example 11ia):

After the hole injection layer, the organic materials specifiedhereinafter are applied to the cleaned substrate by vapor deposition ata rate of approx. 0.5-5 nm/min at about 10⁻⁷-10⁻⁹ mbar. The holeconductor and exciton blocker applied to the substrate is Ir(DPBIC)₃with a thickness of 20 nm, of which the first 10 nm have been doped with10% MoO_(x) to improve the conductivity.

Subsequently, a mixture of 10% emitter Red1 and 90% of the compound Ma7is applied by vapor deposition with a thickness of 6 nm, the lattercompound functioning as matrix material. In a further configuration11ib, the aforementioned mixture is replaced by a mixture of 10% emitterRed1, 60% of the matrix Ma7 and 30% of the matrix Ir(DPBIC)₃.

Subsequently, a mixture of the materials fac-Em1, Ma7 and Ir(DPBIC)₃ isapplied by vapor deposition with a layer thickness of 30 nm. The mixingratio is 40% emitter fac-Em1, 30% of the matrix Ma7 and 30% of thesecond matrix Ir(DPBIC)₃. Subsequently, the material Ma7 is applied witha layer thickness of 10 nm as a hole and exciton blocker. The subsequentelectron conductor layer used is a Cs₂CO₃-doped BCP layer with a layerthickness of 30 nm. An aluminum cathode of thickness 100 nm concludesthe diode.

All components are adhesive bonded to a glass lid in an inert nitrogenatmosphere.

Stacked White (Example 11ic):

After the hole injection layer, the organic materials specifiedhereinafter are applied by vapor deposition to the clean substrate at arate of approx. 0.5-5 nm/min at about 10⁻⁷-10⁻⁹ mbar. The hole conductorand exciton blocker applied to the substrate is Ir(DPBIC)₃ with athickness of 20 nm, of which the first 10 nm have been doped with 10%MoO_(x) to improve the conductivity.

Subsequently, a mixture of the materials fac-Em1, Ma1 and Ir(DPBIC)₃ isapplied by vapor deposition with a thickness of 20 nm. The mixing ratiois 30% emitter fac-Em1, 40% of the matrix Ma1 and 30% of the matrixIr(DPBIC)₃. Subsequently, a pure layer of 10 nm of Ma1 is applied as anexciton and hole blocker.

The subsequent combination of 20 nm of BCP doped with Cs₂CO₃ and 60 nmof Ir(DPBIC)₃ (in a further configuration 11id with 90 nm of Ir(DPBIC)₃)doped with 10% MoO_(x) serves as the charge-generating layer.

Subsequently, Ir(DPBIC)₃ as a hole conductor and exciton blocker isapplied to the substrate with a thickness of 10 nm. Subsequently, amixture of the materials Red1, NPD and Ma17 is applied with a thicknessof 20 nm. The mixing ratio is 10% emitter Red1, 40% of the matrix NPDand 50% of the second matrix Ma17.

Subsequently, a pure layer of 10 nm of BAlq is applied as an exciton andhole blocker.

The subsequent electron conductor layer used is a Cs₂CO₃-doped BCP layerwith a layer thickness of 50 nm. An aluminum cathode of thickness 100 nmconcludes the diode.

All components are adhesive bonded to a glass lid in an inert nitrogenatmosphere.

To characterize the OLED, electroluminescence spectra are recorded atdifferent currents and voltages. In addition, the current-voltagecharacteristic is measured in combination with the light output emitted.The light output can be converted to photometric parameters bycalibration with a photometer.

For the two working examples of a white OLED, the followingelectrooptical data are obtained:

lm/W EQE* @ Ex. CIE @ 1000 nits 1000 nits 11ia 0.33, 0.36 14.8 lm/W13.8% 11ib 0.29, 0.36 16.4 lm/W 12.9% 11ic 0.3, 0.3 18.5 lm/W 30.0% 11id0.35, 0.37 21.5 lm/W 29.3% *EQE—external quantum efficiency. Measured inthe forward direction assuming a Lambertian light intensitydistribution.

Example 11j Liquid-Processed Emission Layer

The ITO substrate used as the anode is cleaned first with commercialdetergents for LCD production (Deconex® 20NS, and 25ORGAN-ACID®neutralizing agent) and then in an acetone/isopropanol mixture in anultrasound bath. To eliminate possible organic residues, the substrateis exposed to a continuous ozone flow in an ozone oven for a further 25minutes. This treatment also improves the hole injection properties ofthe ITO. Next, the hole injection layer AJ20-1000 from Plexcore is spunon from solution.

Thereafter, the hole conductor and exciton blocker Ir(DPBIC)₃ is appliedfrom the liquid phase. For this purpose, a solution of Ir(DPBIC)₃ in THFis spun on with a concentration of 10 mg/ml at a speed of 5000revolutions per minute (rpm) (spin-coating).

Subsequently, the emission layer consisting of the emitter fac-Em1 andthe host Ma7 is likewise applied from the liquid phase. For thispurpose, a solution of fac-Em1 and Ma7 in methylene chloride with aconcentration of 10 mg/m¹ is spun on at a speed of 5000 rpm. The weightratio of the solids between emitter and host is 30:70.

Thereafter, the organic materials mentioned hereinafter are applied byvapor deposition under reduced pressure at a rate of approx. 0.5-5nm/min at about 10⁻⁷-10⁻⁹ mbar to the layers already present.

First, 10 nm of pure Ma7 is applied by vapor deposition as an excitonblocker. Subsequently, the electron conductor ETM1:Liq (50:50) isapplied by vapor deposition with a layer thickness of 20 nm.

The electron injector which then follows is 1 nm of CsF, and 100 nm ofaluminum are applied as a cathode. The component is adhesive bonded to aglass lid in an inert nitrogen atmosphere and exhibits the colorcoordinates CIE x=0.20, y=0.35.

Example 12 Influence of a Mixed Electron Conductor Layer

The electron-transporting layer of the structure described in example 9for fac-Em1 is varied. The following electrooptical data are obtained:

Electron t_(1/2) @ 300 nits conductor lm/W @ (normalized to the (20 nm)CIE 300 nits value of BCP) BCP 0.16, 0.22 3.2 100% BCP:Liq 50% 0.17,0.26 9.0 2780%

Example 13 Emitter Em12 2,3-Bis-(N-4′-methylphenylamino)pyrazine

A mixture of 2,3-dichloropyrazine (13.4 g, 90 mmol) in p-toluidine (21.2g, 198 mmol) is stirred at 110° C. overnight. After cooling to roomtemperature, the mixture is taken up in dichloromethane (200 ml) andextracted by shaking with 25% sodium hydroxide solution. The combinedorganic phases are dried over sodium sulfate and concentrated todryness. The residue is stirred with petroleum ether, filtered off withsuction and washed with cyclohexane. Yield: 15.7 g (60%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=2.30 (s, 6H), 6.24 (br s, 2H), 7.10 (d, 4H),7.18 (d, 4H), 7.67 (s, 2H).

2-Ethoxy-1,3-bis(4′-methylphenyl)pyrazinoimidazoline

A mixture of 2,3-bis(N-4′-methylphenylamino)pyrazine (4.0 g, 14 mmol) intriethyl orthoformate (65 ml) is stirred at 75° C. overnight. Aftercooling to room temperature, the mixture is filtered and the filtrate isconcentrated to dryness. The residue is recrystallized from methyltert-butyl ether. Yield: 3.3 g (70%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=0.99 (t, 3H), 2.32 (s, 6H), 3.24 (q, 2H),7.16 (s, 1H), 7.21 (d, 4H), 7.42 (s, 2H), 7.85 (d, 4H).

Complex fac-Em12

A solution of 2-ethoxy-1,3-bis(4′-methylphenyl)pyrazinoimidazoline (3.5g, 10 mmol) in o-xylene (60 ml) is admixed with 3 Å molecular sieve (6g) and chloro(1,5-cyclooctadiene)iridium(I) dimer (672 mg, 1.0 mmol).The mixture is stirred at 115° C. overnight. After cooling to 80° C.,the residue is filtered off with suction and washed withdichloromethane. The combined filtrates are concentrated to dryness andthe residue is washed with warm isopropanol. The crude product ispurified by column chromatography (silica gel, toluene→dichloromethane).Yield: 0.8 g (37%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=1.85 (s, 9H), 2.06 (s, 9H), 6.44 (s, 3H),6.91 (d, 3H), 7.97 (d, 3H), 8.27 (d, 3H), 8.56 (d, 3H). The 12 protonsof the non-cyclometalated tolyl ring are discernible only as a verybroad elevation in the aromatic region at room temperature owing to therotation of the aromatic system.

Photoluminescence (2% in a PMMA film):

λ_(max)=485 nm, CIE: (0.18; 0.36), QY=85%

Example 14 Emitter Em13 Pyrazine Compound (a)

A mixture of 3,3,5,5-tetramethylcyclopentane-1,2-dione (for synthesissee: T. Laitalainen, Finn. Chem. Lett. 1982, 10) (30.5 g, 188 mmol) andethylenediamine (15.9 ml, 235 mmol) in ethanol (1.45 l) is stirred underreflux overnight. After cooling to 45° C., manganese(IV) oxide (36.0 g,414 mmol) and potassium hydroxide (11.6 g, 207 mmol) are added, and themixture is stirred under reflux for 5 h. After cooling to 70° C., themixture is filtered and the filtrate is neutralized with 10%hydrochloric acid at room temperature. The suspension is filtered andthe filtrate is concentrated to dryness. The residue is column-filteredthrough silica gel with dichloromethane. Yield: 22.7 g (69%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=1.33 (s, 12H), 1.98 (s, 2H), 8.30 (s, 2H).

Pyrazine Compound (b)

A mixture of pyrazine compound (a) (18.1 g, 98 mmol) and water (750 ml)is admixed with potassium peroxomonosulfate (Oxone, 144 g, 234 mmol),and stirred at 50° C. overnight. The aqueous phase is extracted withdichloromethane, washed twice with water, dried over sodium sulfate andconcentrated to dryness. Yield: 17.0 g (84%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=1.51 (s, 12H), 1.97 (s, 2H), 7.78 (s, 2H).

Pyrazine Compound (c)

A mixture of pyrazine compound (b) (18.3 g, 83 mmol) in phosphorylchloride (325 ml) is stirred under reflux overnight. After cooling toroom temperature, the solution is cautiously added dropwise to a mixtureof ice-water (5 l) and dichloromethane (1.5 l). After neutralizationwith concentrated sodium hydroxide solution, the organic phase isremoved, washed three times with water, dried over sodium sulfate andconcentrated to dryness. This affords a mixture of product (approx. 80%)and monochlorinated by-product (approx. 20%), which is used withoutfurther workup. Pure product can be obtained by stirring in petroleumether. Overall yield: 19.2 g (94%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=1.29 (s, 12H), 1.99 (s, 2H).

Pyrazine Compound (d)

A mixture of pyrazine compound (c) (5.5 g, 22 mmol) and aniline (24.6ml, 270 mmol) in o-xylene (65 ml) is stirred at 150° C. overnight. Aftercooling to room temperature, the precipitate is filtered off withsuction and washed with toluene. The combined filtrates are concentratedto dryness in the presence of silica gel. The residue is filteredthrough silica gel with a mixture of cyclohexane and ethyl acetate, andthe filtrate is concentrated to dryness. Yield: 6.6 g (81%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=1.28 (s, 12H), 1.95 (s, 2H), 6.25 (br s,2H), 6.90-6.95 (m, 2H), 7.21-7.27 (m, 8H).

Pyrazine Compound (e)

A mixture of pyrazine compound (d) (0.50 g, 0.7 mmol) in triethylorthoformate (3.5 ml) is admixed with ammonium iodide (0.31 g, 2.1mmol), and stirred at 85° C. for 2 h. After cooling to room temperature,the solids are filtered off with suction, washed with triethylorthoformate, cold ethanol and n-heptane, and dried in a vacuum dryingcabinet at 65° C. Yield: 0.16 g (46%).

¹H NMR (d₆-DMSO, 500 MHz): δ=1.41 (s, 12H), 2.19 (s, 2H), 7.74 (dd, 2H),7.82 (dd, 4H), 8.01 (d, 4H), 10.98 (s, 1H).

Complex fac-Em13

A suspension of pyrazine compound (e) (1.1 g, 2.1 mmol) in dioxane (60ml) is admixed with 4 Å molecular sieve (11 g) and silver(I) oxide (0.5g, 2.1 mmol), and stirred at room temperature overnight. Subsequently, asolution of chloro(1,5-cyclooctadiene)iridium(I) dimer (142 mg, 0.2mmol) in o-xylene (75 ml) is added. The mixture is stirred at refluxovernight. After cooling to 80° C., the residue is filtered off withsuction. The filtrate is concentrated on a rotary evaporator down to avolume of approx. 60 ml and left to stand overnight. The precipitate isfiltered off, washed with toluene and n-hexane and dried in a vacuumdrying cabinet at 85° C. Yield: 0.3 g (57%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=1.15 (s, 9H), 1.35 (s, 9H), 1.46 (s, 9H),1.59 (s, 9H), 2.11 (m_(c), 6H), 6.67 (d, 3H), 6.73 (dd, 3H), 6.79 (dd,3H), 7.14 (dd, 3H), 8.86 (d, 3H). 12 of the 15 protons of thenon-cyclometalated phenyl ring are discernible only as a very broadelevation in the aromatic region at room temperature owing to therotation of the aromatic system.

Photoluminescence (2% in a PMMA film):

λ_(max)=474 nm, CIE: (0.14; 0.24), QY=91%

Example 15 Emitter Em14 2,3-Bis(N-4′-fluorophenylamino)pyrazine

A mixture of 2,3-dichloropyrazine (8.6 g, 58 mmol) and 4-fluoroaniline(66.3 g, 148 mmol) in o-xylene (100 ml) is stirred at 130° C. overnightand at 140° C. for 4 h. After cooling to room temperature, the mixtureis concentrated to dryness and the residue is taken up indichloromethane (300 ml), water (100 ml) and ammonia (25% in water, 100ml). The organic phase is removed, washed twice with water, dried oversodium sulfate and concentrated to dryness. The residue is stirred withpetroleum ether, filtered off with suction and washed with methyltert-butyl ether. Yield: 12.7 g (73%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=6.30 (br s, 2H), 7.03 (dd, 4H), 7.31 (dd,4H), 7.72 (s, 2H).

2-Ethoxy-1,3-bis(4′-fluorophenyl)pyrazinoimidazoline

A mixture of 2,3-bis(N-4′-fluorophenylamino)pyrazine (1.2 g, 4 mmol) intriethyl orthoformate (36 ml) is admixed with sodium sulfate (4.7 g) and5 Å molecular sieve (4.7 g), and stirred at 100° C. for 24 h. Aftercooling to room temperature, the mixture is filtered through sodiumsulfate and cotton wool, and washed with methyl tert-butyl ether. Thecombined filtrates are concentrated to dryness. The residue is stirredwith n-pentane and filtered off with suction. Yield: 0.6 g (42%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=1.01 (t, 3H), 3.26 (q, 2H), 7.08-7.16 (m,5H), 7.46 (s, 2H), 7.98 (dd, 4H).

Complex fac-Em14

A solution of 2-ethoxy-1,3-bis(4′-fluorophenyl)pyrazinoimidazoline (560mg, 1.60 mmol) in o-xylene (60 ml) is admixed with sodium sulfate (4.7g), 5 Å molecular sieve (4.7 g) and chloro(1,5-cyclooctadiene)iridium(I)dimer (107 mg, 0.16 mmol). The mixture is stirred at 110° C. overnight.After again adding chloro(1,5-cyclooctadiene)iridium(I) dimer (107 mg,0.16 mmol), the mixture is stirred at 110° C. for 5 h. After cooling to80° C., the residue is filtered off with suction and washed withdichloromethane. The combined filtrates are concentrated to dryness andthe residue is purified by column chromatography (silica gel,chloroform→toluene). Yield: 133 mg (19%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=6.30 (dd, 3H), 6.84 (ddd, 3H), 8.09 (d, 3H),8.36 (d, 3H), 8.71 (dd, 3H). The 12 protons of the non-cyclometalated4-fluorophenyl ring are discernible only as a very broad elevation inthe aromatic region at room temperature owing to the rotation of thearomatic ring.

Photoluminescence (2% in a PMMA film):

λ_(max)=458 nm, CIE: (0.17; 0.17), QY=58%

Example 16 Emitter Em152-Ethoxy-1,3-diphenyl-2,3-dihydro-1H-imidao[4,5-b]pyrazine

15.30 g (58.3 mmol) of 2,3-Bis(N-phenylamino)pyrazine, 68.00 g of sodiumsulfate and 68.00 g of molecular sieve (4A) are heated to 90° C. in 270ml of triethyl orthoformate for 45 h. After cooling, the solids arefiltered off and washed with methyl tert-butyl ether. The filtrate isfreed of the solvent under reduced pressure. The red-brown oil obtainedis repeatedly stirred with a little n-heptane and dried again underreduced pressure. The residue is purified by column chromatography(silica gel, eluent: 4/1 cyclohexane/acetone). This gives 11.39 g (61%)of 2-ethoxy-1,3-diphenyl-2,3-dihydro-1H-imidao[4,5-b]pyrazine.

¹H NMR (DMSO-D₆, 500 MHz): δ=0.88 (t, 3H), 3.17 (q, 2H), 7.16-7.20 (m,2H), 7.45-7.48 (m, 4H), 7.52 (s, 2H), 7.76 (s, 1H), 8.04-8.06 (m, 4H).

Complex Em15

1.85 g (4.90 mmol) of dichloro(1,5-cyclooctadiene)platinum(II) are addedat room temperature to a solution of 1.85 g (5.82 mmol) of2-ethoxy-1,3-diphenyl-2,3-dihydro-1H-imidazo[4,5-b]pyrazine in 60 ml ofbutanone. The suspension is heated under reflux for 4 hours. Then 1.64 g(7.84 mmol) of silver(I) acetylacetonate are added at room temperature.Thereafter, the mixture is heated under reflux overnight. After cooling,the suspension is filtered. The filtrate is freed of the solvent underreduced pressure and purified by column chromatography (silica gel,eluent: methylene chloride). This gives 0.24 g of Em15 (9%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=1.36 (s, 3H), 2.02 (s, 3H), 5.36 (s, 1H),7.07 (dt, 1H), 7.17 (dt, 1H), 7.57-7.65 (m, 5H), 7.81 (dd, 1H), 8.20(dd, 1H), 8.30 (d, 1H), 8.43 (d, 1H).

Photoluminescence (2% in PMMA film):

λ_(max)=484 nm, CIE: (0.22; 0.34)

Example 17 Emitter Em16 Complex K4

A solution of 0.63 g (0.94 mmol) of bis(1,5-cyclooctadien)diiridium(I)chloride in 50 ml of anhydrous toluene is added dropwise at roomtemperature to a solution of 0.60 g (1.88 mmol) of2-ethoxy-1,3-diphenyl-2,3-dihydro-1H-imidazo[4,5-b]pyrazine in 30 ml ofanhydrous toluene. The mixture is stirred at 60° C. for 30 min and at90° C. for 24 h. After cooling, the solvent is removed under reducedpressure and the residue is purified by column chromatography (silicagel, eluent: 100/1 methylene chloride/methanol). This gives 0.85 g (75%)of K4.

¹H NMR (CD₂Cl₂, 500 MHz): δ=1.32-1.38 (m, 2H), 1.44-1.52 (m, 2H),1.53-1.59 (m, 2H), 1.73-1.81 (m, 2H), 2.55-2.59 (m, 2H), 4.60-4.62 (m,2H), 7.58-7.65 (m, 6H), 8.13-8.15 (m, 4H), 8.29 (s, 2H).

Complex Em16

0.75 g (2.09 mmol) of N,N′-diphenylbenzimidazolium tetrafluoroborate(synthesis analogous to WO2005/019373) in 30 ml of anhydrous toluene areadmixed at 0° C. with 4.20 ml (2.10 mmol) of a 0.5 molar toluenicpotassium hexamethyldisilylamide (KHMDS) solution). The mixture isallowed to thaw to room temperature and is stirred for one hour. Then asolution of 0.61 g (0.99 mmol) of K4 in 150 ml of anhydrous toluene isadded dropwise and the mixture is stirred for a further 30 min.Subsequently, the mixture is heated at reflux for one hour. Aftercooling, the reaction mixture is filtered. The filtrate is freed of thesolvent under reduced pressure and purified by column chromatography(silica gel, eluent: cyclohexane/acetone=4/1). This gives 0.30 g of Em16(30% yield).

¹H NMR (CD₂Cl₂, 500 MHz): δ=6.10-7.20 (very flat, broad signal, 4H),6.19 (br. d, 1H), 6.22-6.25 (m, 2H), 6.37-6.50 (m, 5H), 6.61 (br. d,2H), 6.67 (br. d, 1H), 6.72-6.81 (m, 6H), 7.02-7.17 (m, 5H), 7.27-7.34(m, 4H), 7.95 (d, 1H), 8.00-8.02 (m, 2H), 8.14 (d, 1H), 8.18 (d, 1H),8.26 (d, 1H), 8.71 (d, 1H).

Photoluminescence (2% in PMMA film):

λ_(max)=489 nm, CIE: (0.19; 0.38), 98% QY

Example 18 Preparation of 2,8-di(dibenzofuran-2-yl)dibenzofuran, Ma14

Stage 1:

10.4 g (42.09 mmol) of 2-bromodibenzofuran (prepared according to J.Med. Chem 52(7), 1799-1802, 2009) are weighed into a baked-out 1 lthree-neck round-bottom flask provided with magnetic stirrer,thermometer, septum and nitrogen blanketing. 300 ml of THF (madeabsolute over sodium) are added, and the clear colorless solution iscooled to −78° C. while stirring under an argon atmosphere. Within 30minutes, 17.1 ml (46.3 mmol) of a 2.7 M solution of butyllithium inhexane are added dropwise, in the course of which the internaltemperature is kept at <73° C. This is followed by stirring at thistemperature for a further 30 minutes. Thereafter, 8.61 g (46.3 mmol) of2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane are added dropwiseto the yellow suspension within 40 minutes, in the course of which theinternal temperature is kept at <73° C. This is followed by stirring atthis temperature for a further 60 minutes. The reaction mixture iswarmed to RT and the clear yellow solution is poured onto 200 ml of pH 7buffer, and 23 ml of 2N HCl are added. The solvent is concentrated on aRotavap and the aqueous phase is extracted three times with 250 ml ofEtOAc. The combined organic phases are washed once with 100 ml ofsaturated NaCl solution, dried over magnesium sulfate, filtered andconcentrated. This gives 12.95 g of a white solid which is admixed with50 ml of MeOH and heated to reflux. The clear solution which forms iscooled to room temperature while stirring and then to 0° C. Thesuspension which forms is filtered and the residue is washed twice with10 ml of ice-cold MeOH, and dried at 50° C./120T in a vacuum dryingcabinet overnight. This gives 8.97 g (71.6% of theory) of2-dibenzofuran-2-yl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane in a purityof 98.3%. The NMR and MS data agree with the structure proposed.

Stage 2:

4.09 g (9.73 mmol) of 2,8-diiododibenzofuran (prepared according to J.Amer. Chem. Soc. 124(40), 11900-11907, 2002), 6.30 g (21.04 mmol) of2-dibenzofuran-2-yl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, 6.86 g(49.67 mmol) of potassium carbonate, 180 ml of toluene, 79 ml of EtOHand 37 ml of H₂O₂ are initially charged in a 500 ml three-neck flaskprovided with magnetic stirrer, thermometer, reflux condenser andnitrogen blanketing, and the apparatus is evacuated and filled withargon four times. Subsequently, 1.58 g (1.36 mmol) oftetrakis(triphenylphospine)palladium are added, and the apparatus isevacuated and filled with argon four times. The reaction mixture is thenheated to reflux while stirring vigorously for four hours, then dilutedwith 200 ml of toluene and cooled to room temperature. The phases areseparated and the organic phase is washed twice with 150 ml of water,dried over magnesium sulfate, filtered and concentrated. This gives 5.72g of a brown solid. Purification by means of flash chromatography withhexane/toluene=5:2 as the eluent gives 1.20 g of2,8-di(dibenzofuran-2-yl)dibenzofuran as a white solid with a purity of99.3%. The NMR and MS data agree with the structure proposed.

Example 19 Preparation of Ma7

Ni(COD)₂ (9.03 g, 32.8 mmol), 1,5-cyclooctadiene (3.55 g, 32.8 mmol) and2,2′-bipyridine (5.12 g, 32.8 mmol) are dissolved in dry DMF (140 ml) ina Schlenk flask (glovebox). The mixture is stirred at 80° C. for 30 min.A solution of 9-(8-bromo-dibenzofuran-2-yl)-9H-carbazole (11.75 g, 11.8mmol) in dry toluene (380 ml) is added gradually. After stirring at 80°C. under argon for 24 h, the mixture is cooled to room temperature andadded to MeOH/HCl (1:1, 2000 ml) and stirred for 1 h. The organic phaseis extracted with toluene, dried over Na₂SO₄ and concentrated. LC (SiO₂;cyclohexane/CH₂Cl₂; 4/1) gives Ma7 (9.14 g, 87%).

¹H NMR (400 MHz, CD₂Cl₂): 8.25 (2H, d, J=2 Hz), 8.19 (2H, d, J=2 Hz),8.15 (4H, d, J=8 Hz), 7.88 (1H, d, J=2 Hz), 7.83 (1H, d, J=2 Hz), 7.77(4H, AB, J=8 Hz), 7.65 (1H, d, J=2 Hz), 7.62 (1H, d, J=2 Hz), 7.43-7.38(8H, m), 7.31-7.24 (4H, m).

Example 20 Preparation of Ma12 Stage 1:

t-BuLi (1.7M in pentane) (46.8 ml, 79.4 mmol) is added dropwise at −30°C. under argon to a solution of diphenyl ether (6 ml, 37.8 mmol) in dryTHF (82 ml). The mixture is stirred at −30° C. for 5.5 h and thenphenylsilane (4.64 g, 41.6 mmol) is added. The mixture is stirred at−30° C. for a further 1 h and then warmed to room temperature overnight.Acidified ice (H₂SO₄) is added and the organic phase is extracted withCH₂Cl₂, dried over Na₂SO₄, filtered and concentrated. Recrystallizationfrom MeHO gives 10-phenylphenoxasilin (49%).

¹H NMR (CD₂Cl₂, 400 MHz): 7.57 (2H, dd, J=8.0 Hz, J=1.6 Hz), 7.48-7.35(7H, m), 7.23 (2H, d, J=8.4 Hz), 7.11 (2H, AB, J=7.2 Hz, J=0.8 Hz), 5.50(1H, s).

Stage 2:

n-BuLi (1.6M in hexane) (2.44 ml, 3.9 mmol) is added gradually to asolution of 9-(8-bromodibenzofuran-2yl)-9H-carbazole (1.24 g, 3 mmol) indiethyl ether (60 ml) at 0° C. under Ar. After stirring at 0° C. for 20min, a solution of 10-phenylphenoxasilin (0.99 g, 3.6 mmol) in diethylether (10 ml) is added at 0° C. The mixture is warmed to roomtemperature while stirring overnight. Saturated NH₄Cl solution is added,and the organic phase is extracted with diethyl ether, dried overNa₂SO₄, filtered and concentrated. Recrystallization fromcyclohexane/CH₂Cl₂ gives9-(8-(10-phenyl-10H-dibenzo[b,e][1,4]oxasilin-10-yl)dibenzo[b,d]furan-2-yl)-9H-carbazole(0.92 g) in 51% yield.

¹H NMR (CD₂Cl₂, 400 MHz): 8.16 (1H, s), 8.14 (2H, d, J=8.0 Hz), 8.03(1H, d, J=2.0 Hz), 7.78 (1H, d, J=8.4 Hz), 7.72 (1H, d, J=8.0 Hz), 7.65(1H, d, J=8.4 Hz), 7.62-7.58 (5H, m), 7.46 (2H, t, J=7.4 Hz, J=2.0 Hz),7.40-7.33 (7H, m), 7.33-7.24 (4H, m), 7.13 (2H, t, J=7.2 Hz). ¹³C NMR(CD₂Cl₂, 125 MHz): 110.0, 112.3, 113.3, 116.4, 118.6, 120.3, 120.5,120.6, 123.4, 123.6, 124.4, 125.7, 126.4, 127.3, 128.6, 128.8, 129.3,130.5, 132.2, 133.3, 134.3, 135.7, 136.2, 141.2, 155.6, 158.8, 160.8.

Example 21 Synthesis of Red1

a) 3-Isobutylphenanthro[9,10-b]pyrazine is prepared according to Example9c in patent application WO2009/100991, proceeding from 32.2 g (0.14mol) of dibenzo-[f,h]quinoxaline, with 90 ml (0.15 mol) of a 1.7Msolution of isobutyllithium in heptane, and 50 g of manganese(IV) oxide.The crude product is filtered hot through silica gel and the filtrate isconcentrated under reduced pressure. The resulting solid is stirredovernight in ethanol over a further 18 h. Filtration and washing withethanol gives the product as a pale beige solid (yield: 8.7 g, 31%).

b) 8.0 g (28 mmol) of 3-isobutylphenanthro[9,10-b]pyrazine and 4.82 g(13.2 mmol) of iridium(III) chloride hydrate (iridium content 53.01%)are initially charged at room temperature in 100 ml of 2-ethoxyethanol.The gray-black suspension is stirred at 123° C. over 24 h. The resultingred suspension is filtered, and the solids are washed with ethanol andthen dried further under reduced pressure. The product 21a is obtainedas a red powder (yield: 10.1 g, 95%).

c) 4.95 g (3.1 mmol) of product 21a and 3.3 g (3.1 mmol) of sodiumcarbonate are initially charged in 40 ml of 2-ethoxyethanol and 20 ml ofN,N-dimethylformamide. The red suspension is admixed with 2.5 g (24.8mmol) of acetylacetone and then stirred at 121° C. over 70 min. Theresulting dark red suspension is filtered and the solids are thenstirred once with ethanol and then twice with water, and washed withhexane. The product is obtained as a red powder (yield: 4.3 g, 81%).

¹H NMR (CDCl₃, 400 MHz): δ=1.15 (t, 12H), 1.86 (s, 6H), 2.40-2.50 (m,2H), 3.10-3.15 (m, 4H), 5.35 (s, 1H), 6.45 (d, 2H), 7.04 (6, 2H),7.73-7.82 (m, 4H), 7.93 (d, 2H), 8.56 (d, 2H), 8.67 (s, 2H), 9.33 (d,2H).

Example 22 Emitter Em17 (2-Chloropyridin-3-yl)isopropylamine

12.5 ml (9.7 g, 167.0 mmol) of acetone and 75 ml of glacial acetic acidare added to a solution of 8.0 g (62.2 mmol) of 3-amino-2-chloropyridinein 150 ml of anhydrous dichloromethane. At 0° C., 6.5 ml (5.2 g, 68.4mmol) of borane-dimethyl sulfide complex are added. After evolution ofgas has ended, the mixture is thawed to room temperature and stirredfurther overnight. Then the pH is adjusted to 8 by adding 25% ammoniasolution. 50 ml of water are added. The aqueous phase is extracted threetimes with 50 ml each time of dichloromethane. The combined organicphases are dried over sodium sulfate and freed of the solvent. Thisgives 10.5 g (99%) of yellow oil.

¹H NMR (DMSO-D₆, 500 MHz): δ=1.18 (d, 6H), 3.64 (sept, 1H), 4.96 (d,1H), 7.07 (d, 1H), 7.17 (dd, 1H), 7.57 (dd, 1H).

2-N-Phenylamino-3-N-isopropylaminopyridine

10.5 g (61.5 mmol) of (2-chloropyridin-3-yl)isopropylamine are admixedwith 5.84 g (62.5 mmol) of aniline and the mixture is stirred at 184° C.for 16 h. After cooling to room temperature, 50 ml of water are added.The mixture is stirred for 1 h and aqueous NaOH solution to pH=11adjusted. The mixture is extracted three times with 50 ml each time ofdichloromethane. The combined organic phases are dried over sodiumsulfate and freed of the solvent under reduced pressure. The residue ispurified by column chromatography (silica gel, eluent: cyclohexane/ethylacetate=5/1). This gives 7.5 g (53%) of light brown solid.

¹H NMR (CD₂Cl₂, 500 MHz): δ=1.21 (d, 6H), 3.23 (s br, 1H), 3.57 (sept,1H), 6.26 (s br, 1H), 6.83 (dd, 1H), 6.92-6.99 (m, 2H), 7.25-7.29 (m,4H), 7.70 (dd, 1H).

1-Phenyl-3-isopropylpyridinoimidazolium iodide

7.3 g (32.1 mmol) of 2-N-phenylamino-3-N-isopropylaminopyridine aredissolved in 30 ml of triethyl orthoformate, and 4.8 g (33.1 mmol) ofammonium iodide are added. The reaction mixture is stirred at 82° C.overnight. After cooling, the pale yellow solid formed is filtered off,washed with 3×15 ml of petroleum ether and 3×30 ml of dichloromethaneand dried. This gives 10.2 g (86%) of imidazolium salt.

¹H NMR (DMSO-D₆, 500 MHz): δ=1.72 (d, 6H), 5.19 (sept, 1H), 7.67-7.70(m, 1H), 7.73-7.76 (m, 2H), 7.86-7.88 (m, 1H), 7.95-7.97 (m, 2H),8.81-8.82 (m, 2H), 10.43 (s, 1H).

Complex K5

3.00 g (8.21 mmol) of 1-phenyl-3-isopropylpyridinoimidazolium iodide aresuspended in 45 ml of anhydrous toluene. At −8° C., 16.42 ml of a 0.5molar KHMDS solution in toluene (8.21 mmol) are added. The mixture isthawed to room temperature and stirred for one hour. Then the redsuspension is added at −78° C. to a solution of 2.76 g (4.11 mmol) ofbis(1,5-cyclooctadiene)diiridium(I) chloride in 75 ml of anhydroustoluene. Thereafter, the mixture is heated at room temperature for 1.5hours and at reflux for one hour. After cooling, the reaction mixture isfiltered. The filtrate is freed of the solvent under reduced pressureand purified by column chromatography (silica gel, eluent: methylenechloride). This gives 3.70 g (68%) of complex K5 as a yellow powder.

¹H NMR (CD₂Cl₂, 500 MHz): δ=1.02-1.08 (m, 1H), 1.16-1.21 (m, 1H),1.37-1.42 (m, 1H), 1.59-1.72 (m, 3H), 1.76 (dd, 6H), 2.07-2.18 (m, 2H),2.51-2.55 (m, 1H), 3.15-3.18 (m, 1H), 4.65-4.69 (m, 1H), 4.87-4.91 (m,1H), 6.06 (sept, 1H), 7.23 (dd, 1H), 7.49-7.56 (m, 3H), 7.85 (dd, 1H),8.04-8.06 (m, 2H), 8.22 (dd, 1H).

Complex Em17

A solution of 0.90 g (2.83 mmol) of2-ethoxy-1,3-diphenyl-2,3-dihydro-1H-imidao[4,5-b]pyrazine in 50 ml ofanhydrous o-xylene is admixed successively at room temperature with 10 gof molecular sieve and a solution of 0.86 g (1.29 mmol) of K5 in 75 mlof anhydrous o-xylene. The mixture is stirred at 115° C. for 22 hours.It is cooled and then filtered. The filtrate is freed of the solventunder reduced pressure and purified by column chromatography (silicagel, eluent: cyclohexane/acetone=4/1). This gives 0.53 g (42%) of Em17as a yellow powder.

¹H NMR (CD₂Cl₂, 500 MHz): δ=0.62 (d, 3H), 1.06 (d, 3H), 4.28 (sept, 1H),6.35-7.53 (very flat, broad signal, 8H, ortho- and meta-H of the twononcyclometallated phenyl rings), 6.52 (dd, 1H), 6.59 (dd, 1H), 6.64(dd, 1H), 6.72-6.77 (m, 3H), 6.81 (dt, 1H), 6.97-7.01 (m, 1H), 7.05-7.08(m, 2H), 7.14 (dt, 1H), 7.19 (dt, 1H), 7.41 (dd, 1H), 8.07 (d, 1H), 8.12(d, 1H), 8.34 (dd, 2H), 8.37 (dd, 1H), 8.69 (dd, 1H), 8.80 (dd, 1H),8.95 (dd, 1H).

Photoluminescence (2% in a PMMA film):

λ_(max)=484 nm, CIE: (0.17; 0.34), 95% QY

Example 23 Complex Em18

1.06 g (2.98 mmol) of2-ethoxy-1,3-bis(4-fluorophenyl)-2,3-dihydro-1H-imidao[4,5-b]pyrazine(2-ethoxy-1,3-bis-(4″-fluorophenyl)pyrazinoimidazoline) was added to asolution of 1.00 g (1.49 mmol) of [(μ-Cl)Ir(η⁴-1,5-COD)]₂ in 100 ml ofo-xylene. The resulting solution is subsequently stirred at 65° C. for20 h. After adding 1.80 g (5.66 mmol) of2-ethoxy-1,3-diphenyl-2,3-dihydro-1H-imidazo[4,5-b]pyrazine, thereaction mixture is stirred at 95° C. for a further 48 h. After cooling,the precipitate is filtered off and washed with o-xylene andcyclohexane. The combined organic phases are concentrated to dryness andpurified by column chromatography (silica gel, eluent ethylacetate/cyclohexane=1/4). This gives 0.30 g (20%) of Em18 as a yellowpowder.

¹H NMR (CD₂Cl₂, 500 MHz):

δ=6.20-6.90 (very flat broad signal, 8H), 6.28 (dd, 1H), 6.65 (ddd, 3H),6.59 (d, 1H), 6.80-6.86 (m, 6H), 7.14-7.19 (m, 2H), 8.05 (d, 1H), 8.07(dd, 2H), 8.32 (d, 1H), 8.35 (t, 2H), 8.72 (dd, 1H), 8.76 (dd, 2H).

Photoluminescence (2% in a PMMA film):

λ_(max)=466 nm, CIE: (0.15; 0.19); QY=95%

Example 24 Complex Em19

0.47 g (1.49 mmol) of2-ethoxy-1,3-diphenyl-2,3-dihydro-1H-imidazo[4,5-b]pyrazine was added toa solution of 0.50 g (0.74 mmol) of [(β-Cl)Ir(η⁴-1,5-COD)]₂ in 50 ml ofo-xylene. The resulting solution is subsequently stirred at 60° C. for22 h. After adding 1.04 g (2.94 mmol) of2-ethoxy-1,3-bis(4-fluorophenyl)-2,3-dihydro-1H-imidazo[4,5-b]pyrazine,the reaction mixture is stirred at 95° C. for a further 48 h. Aftercooling, the reaction mixture is concentrated to dryness. The solidresidue is dissolved in dichloromethane/cyclohexane and filtered throughCelite. The filtrate is concentrated to dryness and the residue ispurified by column chromatography (silica gel, eluent ethylacetate/cyclohexane=1/4). This gives 0.17 g (11%) of Em19 as a yellowpowder.

¹H NMR (CD₂Cl₂, 500 MHz):

δ=6.20-6.90 (very flat broad signal, 8H), 6.31 (ddd, 3H), 6.68 (dd, 2H),6.83-6.88 (m, 4H), 7.21 (dt, 1H), 8.10 (dd, 2H), 8.12 (d, 1H), 8.37 (t,2H), 8.40 (d, 1H), 8.71-8.75 (m, 2H), 8.79 (dd, 1H).

Photoluminescence (2% in a PMMA film):

λ_(max)=461 nm, CIE: (0.15; 0.16); QY=90%

Example 25 Emitter Em20 Pyrazine Compound (f)

10.5 g (29.3 mmol) of pyrazine compound (d) and 15.0 g of molecularsieve (5A) are heated to 120° C. in 230 ml of triethyl orthoformate for48 h. After cooling, the solids are filtered off and the filtrate isfreed of the solvent under reduced pressure. The brown oil obtained ispurified by column chromatography (silica gel, eluent: cyclohexane/ethylacetate=9/1). The production fractions are combined and recrystallizedfrom methyl tert-butyl ether. This gives 4.63 g (38%) of pyrazinecompound (f).

¹H NMR (CD₂Cl₂, 500 MHz): δ=1.06 (t, 3H), 1.33 (s, 6H), 1.34 (s, 6H),1.98 (s, 2H), 3.32 (q, 2H), 7.12-7.16 (m, 2H), 7.21 (s, 1H), 7.40-7.47(m, 4H), 8.11-8.16 (m, 4H).

Complex Em20

A solution of 1.9 g (1.8 mmol) of pyrazine compound (f) in 200 ml ofo-xylene (anhydrous) is initially charged with 20 g of molecular sieve,and a solution of 1.26 g (0.8 mmol) of complex K1 in 150 ml of o-xylene(anhydrous) is added. The reaction mixture is subsequently stirred at115° C. for 18 h. After cooling, the reaction mixture is filtered. Thefiltrate is concentrated to dryness, purified by column chromatography(silica gel, eluent cyclohexane/acetone=4/1) and then recrystallizedfrom methylene chloride/methanol. This is followed by anotherpurification by column chromatography (silica gel, eluentcyclohexane/acetone=10/1). This gives 0.75 g (30%) of Em20 as a paleyellow powder.

¹H NMR (CD₂Cl₂, 500 MHz): δ=1.13 (d, 6H), 1.36 (d, 6H), 1.45 (d, 6H),1.58 (d, 6H), 2.03-2.16 (m, 4H), 6.18-6.43 (m, 5H), 6.44-6.97 (m, broad,15H), 6.98-7.22 (m, 6H), 7.32 (t, 1H), 7.99 (d, 1H), 8.17 (d, 1H), 8.78(d, 1H), 8.90 (d, 1H).

Photoluminescence (2% in a PMMA film):

λ_(max)=479 nm, CIE: (0.14; 0.29), 95% QY

Example 26 Emitter Em21 2,3-Di(N-phenylamino)pyridine

A suspension of 2,3-diaminopyridine (8.9 g, 9 mmol) and iodobenzene(17.8 ml, 18 mmol) in dioxane (270 ml) is admixed withtris(dibenzylideneacetone)dipalladium (838 mg, 0.1 mmol),9,9-dimethyl-4,5-bis(diphenylphosphine)xanthene (1.4 g, 0.3 mmol),sodium tert-butoxide (15.4 g, 18 mmol) and water (2.3 g). The mixture isstirred under reflux overnight. After cooling to room temperature, theprecipitate is filtered off with suction and washed withdichloromethane. The combined filtrates are concentrated to dryness andthe residue is dissolved in dichloromethane (125 ml) and cyclohexane(150 ml) and column-filtered. The product fractions are concentrated andprecipitated product is filtered off. Yield: 14.2 g (67%).

¹H NMR (CD₂Cl₂, 500 MHz, 0698403439): δ=5.19 (br s, 1H), 6.71-6.76 (m,3H), 6.84 (dd, 1H), 6.89-6.96 (m, 2H), 7.19 (dd, 2H), 7.23 (dd, 2H),7.39 (d, 1H), 7.51 (d, 2H), 8.02 (d, 1H).

2,3-Di(N-phenylamino)pyridine hydrochloride

A suspension of 2,3-di(N-phenylamino)pyridine (14.2 g, 54 mmol) inhydrochloric acid (200 ml) is stirred at room temperature overnight. Themixture is concentrated to dryness. Yield: 14.0 g (87%).

¹H NMR (d₆-DMSO, 500 MHz, 0698403873): δ=6.94-7.00 (m, 2H), 7.17 (d,2H), 7.30 (m_(c), 3H), 7.40-7.51 (m, 5H), 7.74 (dd, 1H). The NH protonsare undetectable.

1,3-Diphenyl-4-azabenzimidazolium chloride

A mixture of 2,3-di(N-phenylamino)pyridine hydrochloride (14.0 g, 47mmol) in triethyl orthoformate (160 ml) is stirred at 105° C. overnight.After cooling to room temperature, the solids are filtered off withsuction and washed with triethyl orthoformate. Yield: 10.3 g (71%).

¹H NMR (CD₂Cl₂, 500 MHz): δ=7.55-7.73 (m, 7H), 8.08 (dd, 2H), 8.19 (dd,1H), 8.33 (dd, 2H), 8.80 (dd, 1H), 12.24 (s, 1H).

Complex Em21

0.65 g of 1,3-diphenyl-4-azabenzimidazolium chloride (2.1 mmol) issuspended in 100 ml of anhydrous toluene and cooled to 0° C. Then 4.2 mlof potassium bis(trimethylsilyl)amide (KHMDS, 0.5M in toluene, 2.1 mmol)are added gradually. The mixture is stirred at room temperature for 1 hand then a solution of 0.61 g of K4 (1.0 mmol) in 100 ml of anhydroustoluene is added. The mixture is stirred at room temperature for 1 h andthen heated at reflux for 18 h. The mixture is cooled and thenconcentrated to dryness. The residue is purified by columnchromatography (silica gel, eluent: cyclohexane/acetone=4/1). This gives0.13 g (13%) of Em21 as a pale yellow powder.

¹H NMR (CD₂Cl₂, 500 MHz): δ=6.23-6.32 (m, 3H), 6.38 (t, 1H), 6.40-6.85(m, 17H), 7.00-7.05 (m, 2H), 7.10-7.16 (m, 3H), 7.32 (t, 2H), 8.01 (d,1H), 8.28 (d, 1H), 8.39 (dt, 2H), 8.72 (d, 1H), 8.94 (d, 1H), 8.98 (d,1H).

Photoluminescence (2% in a PMMA film):

λ_(max)=480 nm, CIE: (0.17; 0.30), 95% QY

Example 27 Emitter Em22

A solution of 2.30 g (6.4 mmol) of1-(4-cyanophenyl)-3-methylbenzimidazolium iodide (for preparation seeWO2006/056418) in 200 ml of 1,4-dioxane (anhydrous, ultradry) is admixedwith 1.11 g (4.8 mmol) of silver(I) oxide and 20 g of molecular sieve,and stirred at room temperature overnight. Then a solution of 1.29 g(2.1 mmol) of complex K4 in 200 ml of anhydrous o-xylene is added andthe mixture is stirred at 110° C. for 22 h. After cooling, the reactionmixture is filtered. The filtrate is freed of the solvent under reducedpressure and then separated by column chromatography (silica gel,eluent: cyclohexane/acetone=2/1). This gives 0.61 g (31%) of Em22 isomer1 (RF=0.31), 0.45 g (23%) of Em22 isomer 2 (RF=0.25) and 0.25 g (13%) ofEm22 isomer 3 (RF=0.20), each of which are recrystallized once more frommethylene chloride/methanol.

Em22 Isomer 1:

¹H NMR (CD₂Cl₂, 500 MHz): δ=2.78 (s, 3H), 3.15 (s, 3H), 6.31 (d, verybroad, 2H), 6.53 (d, 1H), 6.68 (t, 1H), 6.77 (t, 1H), 6.92 (d, 1H),7.11-7.16 (m, 2H), 7.23-7.52 (m, 10H), 7.88 (d, 1H), 7.91 (d, 1H), 7.99(d, 1H), 8.11 (d, 1H), 8.18 (d, 1H), 8.41 (d, 1H), 8.76 (d, 1H).

Photoluminescence (2% in a PMMA film):

λ_(max)=484 nm, CIE: (0.19; 0.33), 87% QY

Em22 Isomer 2:

¹H NMR (CD₂Cl₂, 500 MHz): δ=3.20 (s, 3H), 3.37 (s, 3H), 5.67-6.92 (veryflat broad signal, 2H), 6.51 (d, 1H), 6.70-6.77 (m, 2H), 6.97-7.00 (m,1H), 7.06-7.12 (m, 3H), 7.20-7.47 (m, 10H), 7.90 (d, 1H), 8.06 (t, 2H),8.24 (d, 1H), 8.45 (d, 1H), 8.80 (d, 1H).

Photoluminescence (2% in a PMMA film):

λ_(max)=494 nm, CIE: (0.22; 0.41), 87% QY

Em22 Isomer 3:

¹H NMR (CD₂Cl₂, 500 MHz): δ=2.75 (s, 3H), 3.56 (s, 3H), 6.02-7.26 (veryflat broad signal, 4H), 6.48 (dd, 1H), 6.68 (d, 1H), 6.69-6.73 (m, 1H),6.78 (dt, 1H), 6.86 (d, 1H), 6.90 (d, broad, 1H), 7.14 (dt, 1H), 7.24(dt, 1H), 7.30-7.39 (m, 5H), 7.49 (dd, 1H), 7.87 (d, 1H), 7.94 (d, 1H),8.03 (d, 1H), 8.08 (d, 1H), 8.17 (d, 1H), 8.41 (d, 1H), 8.79 (dd, 1H).

Photoluminescence (2% in a PMMA film):

λ_(max)=468 nm, CIE: (0.16; 0.21), 90% QY

Example 28 Production of Doped OLEDs

The ITO substrate used as the anode is cleaned first with commercialdetergents for LCD production (Deconex® 20NS, and 25ORGAN-ACID®neutralizing agent) and then in an acetone/isopropanol mixture in anultrasound bath. To eliminate possible organic residues, the substrateis exposed to a continuous ozone flow in an ozone oven for a further 25minutes. This treatment also improves the hole injection properties ofthe ITO. Next, the hole injection layer AJ20-1000 from Plexcore is spunon from solution.

Example 28a

After the hole injection layer, the organic materials specifiedhereinafter are applied at a rate of approx. 0.5-5 nm/min to the cleanedsubstrate at about 10⁻⁷-10⁻⁹ mbar. The hole conductor applied by vapordeposition is 20 nm of the mixture of Ir(DPBIC)₃ with 4% of the p-dopantF6-TNAP. The exciton blocker applied to the substrate is Ir(DPBIC)₃ witha thickness of 10 nm.

(for preparation of Ir(DPBIC)₃ see Ir complex (7) in the application WO2005/019373 A2).

Subsequently, a mixture of 30% emitter fac-Em1, 60% of the compound Ma7and 10% of the compound Ir(DPBIC)₃ with a thickness of 30 nm is appliedby vapor deposition as an emissive layer, the latter two compoundsfunctioning as matrix material.

The subsequent electron conductor layer used is an ETM2 layer (seecompound No. 28 in EP1097981) doped with 8% W(hpp)₄ (see EP1786050) witha layer thickness of 25 nm.

An aluminum cathode of thickness 100 nm concludes the diode.

All components are encapsulated with a glass lid in an inert nitrogenatmosphere.

Example 28b

The OLED from Example 28b is of the same structure as the OLED fromExample 28a, except with the difference that the emissive layer consistsof 30% Em8 and 70% matrix material Ma7.

To characterize the OLEDs, electroluminescence spectra are recorded atdifferent currents and voltages. In addition, the current-voltagecharacteristic is measured in combination with the light output emitted.The light output can be converted to photometric parameters bycalibration with a photometer.

For the two working examples of a doped OLED, the followingelectrooptical data are obtained:

Ex. Emitter Voltage [V] at 300 nits EQE [%] at 300 nits 28a fac-Em1 2.75V 10.9% 28b Em8 3.38 V 10.8% *EQE—external quantum efficiency. Measuredin forward direction assuming a Lambertian light intensity distribution.

Example 29 Diodes with Different Emitters

The ITO substrate used as the anode is cleaned first with commercialdetergents for LCD production (Deconex® 20NS, and 25ORGAN-ACID®neutralizing agent) and then in an acetone/isopropanol mixture in anultrasound bath. To eliminate possible organic residues, the substrateis exposed to a continuous ozone flow in an ozone oven for a further 25minutes. This treatment also improves the hole injection properties ofthe ITO. Next, the 40 nm-thick hole injection layer, AJ20-1000 fromPlexcore, is spun on from solution.

Thereafter, the organic materials specified below are applied by vapordeposition at a rate of approx. 0.5-5 nm/min to the clean substrate atabout 10⁻⁷-10⁻⁹ mbar.

The hole conductor and exciton blocker applied is Ir(DPBIC)₃ in athickness of 20 nm, of which the first 15 nm have been doped with 5%ReO₃. Thereafter, a 20 nm-thick emission layer consisting of an emitterand two matrix materials is applied by vapor deposition. This isfollowed by a 5 nm-thick layer of exciton and hole blocker. Next, amixture of 50% Liq and 50% ETM1 as an electron transport layer isapplied in a thickness of 40 nm. Finally, a 4 nm-thick layer of KF and a100 nm-thick Al electrode are applied by vapor deposition.

Example 29a

The diode is constructed as described above with an emission layerconsisting of 10% of the emitter Em16 and 45% each of the matrixmaterials Ir(DPBIC)₃ and Ma13. The exciton and hole blocker used isMa13.

The diode exhibits the color coordinates CIE 0.20, 0.43. At 300 cd/m²,the voltage is 3.6 V and the external quantum efficiency 17.7%.

Example 29b

The diode is constructed as described above with an emission layerconsisting of 10% of the emitter Em16 and 45% each of the matrixmaterials Ir(DPBIC)₃ and Ma7. The exciton and hole blocker used is Ma7.

The diode exhibits the color coordinates CIE 0.19, 0.43. At 300 cd/m²,the voltage is 3.6 V and the external quantum efficiency 14.7%.

Example 29c

The diode is constructed as described above with an emission layerconsisting of 10% of the emitter Em17 and 45% each of the matrixmaterials Ir(DPBIC)₃ and Ma13. The exciton and hole blocker used isMa13.

The diode exhibits the color coordinates CIE 0.20, 0.44. At 300 cd/m²,the luminous efficiency is 45.5 lm/W and the external quantum efficiency19.6%.

Example 29d

The diode is constructed as described above with an emission layerconsisting of 10% of the emitter Em17 and 45% each of the matrixmaterials Ir(DPBIC)₃ and Ma7. The exciton and hole blocker used is Ma7.

The diode exhibits the color coordinates CIE 0.18, 0.39. At 300 cd/m²,the voltage is 3.8 V and the luminous efficiency 40.4 Im/W.

Example 29e

The diode is constructed as described above with an emission layerconsisting of 10% of the emitter Em20 and 45% each of the matrixmaterials Ir(DPBIC)₃ and Ma7. The exciton and hole blocker used is Ma7.

The diode exhibits the color coordinates CIE 0.15, 0.29. At 300 cd/m²,the voltage is 3.6 V and the external quantum efficiency 19.9%.

Example 29f

The diode is constructed as described above with an emission layerconsisting of 10% of the emitter Em20 and 45% each of the matrixmaterials Ir(DPBIC)₃ and Ma13. The exciton and hole blocker used isMa13.

The diode exhibits the color coordinates CIE 0.15, 0.29. At 300 cd/m²,the voltage is 3.3 V and the external quantum efficiency 19.0%.

Example 30 Homolunction OLEDs Example 30a

The ITO substrate used as the anode is cleaned first with commercialdetergents for LCD production (Deconex® 20NS, and 25ORGAN-ACID®neutralizing agent) and then in an acetone/isopropanol mixture in anultrasound bath. To eliminate possible organic residues, the substrateis exposed to a continuous ozone flow in an ozone oven for a further 25minutes. This treatment also improves the hole injection properties ofthe ITO. Next, the 40 nm-thick hole injection layer, AJ20-1000 fromPlexcore, is spun on from solution.

Thereafter, the organic materials specified below are applied by vapordeposition at a rate of approx. 0.5-5 nm/min to the clean substrate atabout 10⁻⁷-10⁻⁹ mbar.

The hole conductor and exciton blocker applied is Ma4 in a thickness of20 nm, of which the first 15 nm have been doped with 5% ReO₃.Thereafter, a 20 nm-thick emission layer consisting of 10% fac-Em1, 35%Ir(DPBIC)₃ and 55% Ma4 is applied by vapor deposition. This is followedby a 5 nm-thick layer of Ma4 of exciton and hole blocker. Next, amixture of 50% Liq and 50% Ma4 as an electron transport layer is appliedin a thickness of 40 nm. Finally, a 4 nm-thick layer of KF and a 100nm-thick Al electrode are applied by vapor deposition.

The diode exhibits the color coordinates CIE 0.15, 0.25. At 300 cd/m²,the external quantum efficiency is 18.7%.

Example 30b

The diode is constructed analogously to Example 30a with the differencethat the emission layer consists of 30% fac-Em1, 35% Ir(DPBIC)₃ and 35%Ma4.

The diode exhibits the color coordinates CIE 0.16, 0.31. At 300 cd/m²,the external quantum efficiency is 16.2%.

Example 30c

The diode is constructed analogously to Example 30a with the differencethat Ma4 is replaced by Ma7 in the particular layers and the emissionlayer consists of 10% fac-Em1, 45% Ir(DPBIC)₃ and 45% Ma7.

The diode exhibits the CIE color coordinates 0.16, 0.28. At 300 cd/m²the external quantum efficiency is 11.9%.

Example 30d

The diode is constructed analogously to Example 30a with the differencethat Ma4 is replaced by Ma7 in the particular layers and the emissionlayer consists of 30% fac-Em1, 35% Ir(DPBIC)₃ and 35% Ma7.

The diode exhibits the CIE color coordinates 0.18, 0.34. At 300 cd/m²the external quantum efficiency is 16.3%.

Example 31 Synthesis of ETM3

Stage 1

A 250 ml three-neck round-bottom flask provided with magnetic stirrer,thermometer, dropping funnel, reflux condenser and nitrogen blanketingis initially charged with 150 ml of methanol, and 3.8 g of potassiumhydroxide (≧85%) are added. The mixture is stirred at room temperatureuntil a clear colorless solution forms. Subsequently, an ice bath isused to cool it to 0° C., and 14.3 g (56.7 mmol) of1-(8-acetyldibenzofuran-2-yl)ethanone (prepared according to M. J.Bruce, Perkin Transactions 1,1789 (1995)) are added. The suspension isstirred at 0° C. for 1 h and then 17.3 ml (170 mmol) of benzaldehyde areadded dropwise within 3 min. The reaction mixture is subsequently warmedto room temperature and stirred for 14 h. The fine beige-yellowsuspension is filtered and the residue is washed with 50 ml of ethanol.The crude product is suspended in 150 ml of ethanol and stirred underreflux for 30 min. Then it is cooled to room temperature and then to 0°C., filtered and washed twice with 10 ml of ice-cold ethanol, and theresidue is dried at 50° C./150 mbar overnight. This gives 21.6 g (88.9%of theory) of3-phenyl-1-{8-(3-phenylacryloyl)]-dibenzofuran-2-yl}propenone as palebeige crystals.

¹H NMR (CDCl₃, 300 MHz):

8.67 (s, 2H), 8.25 (d, J=7 Hz, 2H), 7.89 (s, J=12 Hz, 2H), 7.8-7.65 (m,8H), 7.55-7.4 (m, 6H).

Stage 2

A 100 ml three-neck round-bottom flask provided with magnetic stirrer,thermometer, reflux condenser and nitrogen blanketing is initiallycharged with 60 ml of methanol and cooled to 0° C. with an ice bathwhile stirring. Subsequently, 15.7 g (240 mmol) of potassiumtert-butoxide are added in portions within 10 min. A 500 ml three-neckround-bottom flask provided with magnetic stirrer, thermometer, droppingfunnel, reflux condenser and nitrogen blanketing is initially chargedwith 90 ml of methanol, and then 8.6 g (20 mmol) of3-phenyl-1-{8-(3-phenylacryloyl)]dibenzofuran-2-yl}propenone and 41.8 g(80 mmol) of benzamidine hydrochloride (30% in methanol) are added whilestirring. The beige suspension is heated to reflux and then thepotassium tert-butoxide solution previously prepared is added dropwisewithin 20 min. The beige-brown suspension is stirred under refluxovernight. Subsequently, it is cooled to room temperature and then 150ml of water are added dropwise and the mixture is stirred for 4 h. Asuspension forms, which is filtered. The residue is suspended in 200 mlof water and heated to reflux for 2 h. Subsequently, the mixture iscooled to room temperature and filtered, and the residue is washed with50 ml of water and then dried at 60° C./150 mbar overnight. This gives10.9 g of 2,8-bis(2,4-diphenyl-1,4-dihydro-pyrimidinyl)dibenzofuran(85.8% of theory) as yellow crystals. The crude product is used furtherwithout purification.

Stage 3

A 500 ml three-neck round-bottom flask provided with magnetic stirrer,thermometer, reflux condenser and nitrogen blanketing is initiallycharged with 10.9 g (17 mmol) of crude2,8-bis(2,4-diphenyl-1,4-dihydropyrimidinyl)dibenzofuran in 100 ml ofo-dichloro-benzene and heated to 60° C. while stirring. Thereafter, 19.1g (78 mmol) of chloranil are added and the dark-colored reaction mixtureis heated to reflux for 14 h. Subsequently, 160 ml of MeOH are added andthe mixture is stirred under reflux for 15 min. Thereafter, it is cooledto 0° C. with an ice bath, the dark brown suspension is filtered and theresidue is washed three times with 50 ml each time of MeOH and twicewith 50 ml each time of water. After drying at 60° C./125 mbarovernight, 18.0 g of brown crystals are obtained. The crude product issuspended in 100 ml of MeOH under reflux for 1 h, then cooled to 0° C.,washed twice with 20 ml each time of MeOH and dried at 60° C./125 mbar.This gives 16.4 g of brown crystals. 5.7 g of this material aresuspended in 50 ml of EtOH under reflux for 30 min, then cooled to 0°C., washed twice with 20 ml each time of EtOH and dried at 60° C./125mbar. This gives 5.0 g of brown crystals. This crude product is slurriedin 190 ml of toluene and stirred under reflux for 30 min. Thereafter, itis cooled to 0° C. with an ice bath, the suspension is filtered and theresidue is washed three times with 20 ml each time of toluene. Afterdrying at 60° C./125 mbar overnight, 3.0 g (81% of theory) of thedesired product are obtained as white-beige crystals.

HPLC-MS: purity 99.5%, [M+1]=629.5 m/z.

¹H NMR (CDCl₃, 300 MHz):

8.97 (s, 2H), 8.73 (d, J=9 Hz, 4H), 8.43 (d, J=10 Hz, 2H), 8.42-8.28 (m,4H), 8.11 (s, 2H), 7.73 (d, J=9 Hz, 2H) 7.60-7.35 (m, 12H)

Example 32

First, the ITO substrate used as the anode is treated as in Example 30aand provided with a 40 nm-thick hole injection layer of AJ20-1000 fromPlexcore as described above.

Thereafter, the organic materials specified hereinafter are applied byvapor deposition at a rate of approx. 0.5-5 nm/min to the cleansubstrate at about 10⁻⁷-10⁻⁹ mbar:

Example 32a

The hole conductor and exciton blocker applied is Ir(DPBIC)₃ in athickness of 20 nm, of which the first 15 nm have been doped with 5%ReO₃. Thereafter, a 20 nm-thick emission layer consisting of 10%fac-Em1, 45% Ir(DPBIC)₃ and 45% Ma13 is applied by vapor deposition.This is followed by a 5 nm-thick layer Ma13 of exciton and hole blocker.Next, a mixture of 50% Liq and 50% ETM3 as an electron transport layeris applied in a thickness of 40 nm. Finally, a 4 nm-thick layer of KFand a 100 nm-thick Al electrode are applied by vapor deposition.

The diode exhibits the CIE color coordinates 0.16, 0.27. At 300 cd/m²,the external quantum efficiency is 13.7%.

Example 32b

The diode is constructed as described in Example 32a with the differencethat the electron transport layer consists of pure ETM3.

The diode exhibits the CIE color coordinates 0.16, 0.27. At 300 cd/m²,the voltage is 3.4 V.

Example 32c

The diode is constructed as described in Example 32a with the differencethat the emission layer consists of 30% fac-Em1, 35% Ir(DPBIC)₃ and 35%Ma13.

The diode exhibits the CIE color coordinates 0.17, 0.32. At 300 cd/m²,the voltage is 3.4 V.

Example 32d

The diode is constructed as described in Example 32c with the differencethat the electron transport layer consists of pure ETM3.

The diode exhibits the CIE color coordinates 0.17, 0.31. At 300 cd/m²,the external quantum efficiency is 14.2%.

Example 33 Synthesis of ETM4

Stage 1

A 100 ml three-neck round-bottom flask, magnetic stirrer, thermometer,reflux condenser, gas inlet tube, nitrogen blanketing and gas washbottle is initially charged with 1.09 g (5.0 mmol) ofdibenzofuran-2,8-dicarbonitrile (prepared according to S. Wang, Eur. J.Med. Chem. 34, 215 (1999)) in a mixture of 1.8 ml of ethanol and 50 mlof 1,4-dioxane, and is cooled to 0° C. with an EtOH/CO₂ bath, and thenHCl gas is introduced until saturation. Thereafter, the flask is sealedand the white suspension is warmed to RT and stirred for 48 h.Subsequently, dry N₂ is blown into the suspension until no HCl can bedetected any longer in the offgas. 25 ml of t-butyl methyl ether areadded and the yellowish suspension is filtered. The residue is washedtwice with 25 ml each time of t-butyl methyl ether, then suspended in 40ml of 2M H₃ in ethanol and stirred at 60° C. for 18 h. Subsequently, thesuspension is cooled and dry N₂ is blown into the suspension until noNH₃ can be detected any longer in the offgas. Then it is cooled with anice bath and HCl gas is again introduced until saturation. Thereafter,it is blown out again with dry N₂, and the beige suspension is filteredand washed with portions totaling 25 ml of ice-cold EtOH. The residue isdried at 50° C./125 mbar overnight. This gives 1.71 g (99.2% of theory)of dibenzofuran-2,8-bisamidine hydrochloride as beige crystals.

¹H NMR (DMSO, 300 MHz):

8.90-8.75 (m, 2H), 8.25-8.00 (m, 4H)

Stage 2

A 100 ml three-neck round-bottom flask provided with magnetic stirrer,thermometer, reflux condenser and nitrogen blanketing is initiallycharged with 40 ml of methanol and cooled to 0° C. with an ice bathwhile stirring. Subsequently, 2.85 g (25.4 mmol) of potassiumtert-butoxide are added in portions within 10 min. A 250 ml three-neckround-bottom flask provided with magnetic stirrer, thermometer, droppingfunnel, reflux condenser and nitrogen blanketing is initially chargedwith 60 ml of methanol and then 1.7 g of dibenzofuran-2,8-bisamidinehydrochloride and 4.08 g (19 mmol) of benzylidenacetophenone are addedwhile stirring. The beige suspension is heated to reflux and then thepreviously prepared potassium tert-butoxide solution is added dropwisewithin 5 min. The beige suspension is stirred under reflux overnight.Subsequently, the mixture is cooled to 0° C. and filtered, and theresidue is washed with 15 ml of ice-cold MeOH and three times with 60 mlof water, and dried at 60° C./150 mbar overnight. This gives 1.59 g of2,8-bis(4,6-diphenyl-1,4-dihydro-pyrimidinyl)dibenzofuran (39.6% oftheory) as yellow crystals. The crude product is used further withoutpurification.

Stage 3

A 100 ml three-neck round-bottom flask provided with magnetic stirrer,thermometer, reflux condenser and nitrogen blanketing is initiallycharged with 1.59 g (2.45 mmol) of2,8-di(4,6-diphenyl-1,4-dihydropyrimidinyl)dibenzofuran in 15 ml ofo-dichlorobenzene. The mixture is heated to internal temperature 50° C.while stirring and then 2.41 g (9.80 mmol) of chloranil are added. Thebeige-brown suspension is heated to reflux for 4 h, then 30 ml of MeOHand subsequently 1 g of NaOH dissolved in 5 ml of water are addeddropwise. The dark brown suspension is stirred under reflux for 30 min,then cooled to 0° C. with an ice bath and filtered. The residue iswashed three times with 20 ml of MeOH and five times with 20 ml of hotwater. The beige solid is suspended in 50 ml of toluene and refluxedwhile stirring for 30 min. This is followed by cooling to an internaltemperature of 60° C. and filtration, and the residue is washed twicewith 10 ml of toluene and dried at 60° C./125 mbar overnight. This gives0.85 g (55.2% of theory) of the desired product as white crystals.

HPLC-MS: purity 99.3%, [M+1]=629.5 m/z.

¹H NMR (CDCl₃, 300 MHz):

9.41 (s, 2H), 8.89 (d, J=9 Hz, 2H), 8.35-8.20 (m, 8H), 7.98 (s, 2H),7.68 (d, J=9 Hz, 2H) 7.70-7.45 (m, 12H)

1. A metal-carbene complex of the general formula (I):

wherein M is Ir or Pt, n is an integer from 1, 2 or 3, Y is NR¹, O, S orC(R¹⁰)₂, A², A³, A⁴, A⁵ are each independently N or C, where 2A=nitrogen atoms and at least one carbon atom is present between twonitrogen atoms in the ring, R¹ is a linear or branched alkyl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having 1 to 20 carbon atoms, cycloalkylradical optionally interrupted by at least one heteroatom, optionallybearing at least one functional group and having 3 to 20 carbon atoms,substituted or unsubstituted aryl radical optionally interrupted by atleast one heteroatom, optionally bearing at least one functional groupand having 6 to 30 carbon atoms, substituted or unsubstituted heteroarylradical optionally interrupted by at least one heteroatom, optionallybearing at least one functional group and having a total of 5 to 18carbon atoms and/or heteroatoms, R², R³, R⁴, R⁵ are each, if A², A³, A⁴and/or A⁵ is N, a free electron pair, or, if A², A³, A⁴ and/or A⁵ is C,each independently hydrogen, linear or branched alkyl radical optionallyinterrupted by at least one heteroatom, optionally bearing at least onefunctional group and having 1 to 20 carbon atoms, cycloalkyl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having 3 to 20 carbon atoms, substitutedor unsubstituted aryl radical optionally interrupted by at least oneheteroatom, optionally bearing at least one functional group and having6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having a total of 5 to 18 carbon atomsand/or heteroatoms, group with donor or acceptor action, or R³ and R⁴together with A³ and A⁴ form an optionally substituted, unsaturated ringoptionally interrupted by at least one further heteroatom and having atotal of 5 to 18 carbon atoms and/or heteroatoms, R⁶, R⁷, R⁸, R⁹ areeach independently hydrogen, linear or branched alkyl radical optionallyinterrupted by at least one heteroatom, optionally bearing at least onefunctional group and having 1 to 20 carbon atoms, cycloalkyl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having 3 to 20 carbon atoms,cycloheteroalkyl radical optionally interrupted by at least oneheteroatom, optionally bearing at least one functional group and having3 to 20 carbon atoms, substituted or unsubstituted aryl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having 6 to 30 carbon atoms, substitutedor unsubstituted heteroaryl radical optionally interrupted by at leastone heteroatom, optionally bearing at least one functional group andhaving a total of 5 to 18 carbon atoms and/or heteroatoms, with a baseskeleton selected from the group consisting of pyridyl, pyrimidyl,pyrazyl, triazolyl, pyrrole, furan, thiophene, pyrazole, triazole,oxazole and thiazole, group with donor or acceptor action, at least oneselected from the group consisting of a halogen radical, a silylradical, a siloxy radical, an alkoxy radical, an aryloxy radical, acarbonyl radical, an ester radical, CH₂F, CHF₂, CF₃, CN, a thio groupand SCN, or R⁶ and R⁷, R⁷ and R⁸ or R⁸ and R⁹, together with the carbonatoms to which they are bonded, form a saturated, unsaturated oraromatic, optionally substituted ring optionally interrupted by at leastone heteroatom and having a total of 5 to 18 carbon atoms and/orheteroatoms, and/or if A⁵ is C, R⁵ and R⁶ together form a saturated orunsaturated, linear or branched bridge optionally comprisingheteroatoms, an aromatic unit, heteroaromatic unit and/or functionalgroups and having a total of 1 to 30 carbon atoms and/or heteroatoms, towhich is optionally fused a substituted or unsubstituted, five- toeight-membered ring comprising carbon atoms and/or heteroatoms, R¹⁰ isindependently a linear or branched alkyl radical optionally interruptedby at least one heteroatom, optionally bearing at least one functionalgroup and having 1 to 20 carbon atoms, cycloalkyl radical optionallyinterrupted by at least one heteroatom, optionally bearing at least onefunctional group and having 3 to 20 carbon atoms, substituted orunsubstituted aryl radical optionally interrupted by at least oneheteroatom, optionally bearing at least one functional group and having6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having a total of 5 to 18 carbon atomsand/or heteroatoms, K is an uncharged mono- or bidentate ligand, L is amono- or dianionic ligand, m is 0, 1 or 2, where, when m is 2, the Kligands may be the same or different, and o is 0, 1 or 2, where, when ois 2, the L ligands may be the same or different.
 2. The metal-carbenecomplex according to claim 1, wherein: M is Ir, n is 1, 2 or 3, Y isNR¹, A², A³, A⁴, A⁵ are each independently N or C, where 2 A=nitrogenatoms and at least one carbon atom is present between two nitrogen atomsin the ring, R¹ is a linear or branched alkyl radical having 1 to 6carbon atoms, substituted or unsubstituted aryl radical having 6 to 30carbon atoms, substituted or unsubstituted heteroaryl radical having atotal of 5 to 18 carbon atoms and/or heteroatoms, R², R³, R⁴, R⁵ areeach, if A², A³, A⁴ and/or A⁵ is N, a free electron pair, or, if A², A³,A⁴ and/or A⁵ is C, each independently hydrogen, linear or branched alkylradical having 1 to 6 carbon atoms, substituted or unsubstituted arylradical having 6 to 30 carbon atoms, substituted or unsubstitutedheteroaryl radical having a total of 5 to 18 carbon atoms and/orheteroatoms, or R³ and R⁴ together with A³ and A⁴ form an optionallysubstituted, unsaturated ring optionally interrupted by at least onefurther heteroatom and having a total of 5 to 18 carbon atoms and/orheteroatoms, R⁶, R⁷, R⁸, R⁹ are each independently hydrogen, linear orbranched alkyl radical optionally interrupted by at least oneheteroatom, optionally bearing at least one functional group and having1 to 20 carbon atoms, substituted or unsubstituted aryl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having 6 to 30 carbon atoms, substitutedor unsubstituted heteroaryl radical optionally interrupted by at leastone heteroatom, optionally bearing at least one functional group andhaving a total of 5 to 18 carbon atoms and/or heteroatoms, with a baseskeleton selected from the group consisting of pyridyl, pyrimidyl,pyrazyl, triazolyl, pyrrole, furan, thiophene, pyrazole, triazole,oxazole and thiazole, L is a monoanionic bidentate ligand, m is 0, and ois 0, 1 or
 2. 3. The metal-carbene complex according to claim 1,wherein: M is Ir, n is 2 or 3, Y is NR¹, A², A³, A⁴, A⁵ A² and A⁵ areeach N and A³ and A⁴ are each C or A² and A⁴ are each N and A³ and A⁵are each C or A³ and A⁵ are each N and A² and A⁴ are each C, R¹ is alinear or branched alkyl radical having 1 to 6 carbon atoms, substitutedor unsubstituted phenyl radical, substituted or unsubstituted heteroarylradical having a total of 6 to 18 carbon atoms and/or heteroatoms, R²,R³, R⁴, R⁵ are each, if A², A³, A⁴ and/or A⁵ is N, a free electron pairor, if A², A³, A⁴ and/or A⁵ is C, each independently hydrogen, linear orbranched alkyl radical having 1 to 6 carbon atoms, substituted orunsubstituted phenyl radical, or R³ and R⁴ together with A³ and A⁴ forman optionally substituted, monounsaturated ring having a total of 5 to 7carbon atoms, R⁶, R⁷, R⁸, R⁹ are each independently hydrogen, linear orbranched alkyl radical having 1 to 20 carbon atoms, o,o′-dialkylatedaryl radical having 6 to 30 carbon atoms, L is a monoanionic bidentateligand, m is 0, o is 0 or
 1. 4. The metal-carbene complex of claim 1,wherein, in the general formula (I), L is a carbene ligand of thegeneral formula (II):

wherein A⁶, A⁷ are each independently C or N, R¹¹ is a linear orbranched alkyl radical optionally interrupted by at least oneheteroatom, optionally bearing at least one functional group and having1 to 20 carbon atoms, cycloalkyl radical optionally interrupted by atleast one heteroatom, optionally bearing at least one functional groupand having 3 to 20 carbon atoms, cycloheteroalkyl radical optionallyinterrupted by at least one heteroatom, optionally bearing at least onefunctional group and having 3 to 20 carbon atoms, substituted orunsubstituted aryl radical optionally interrupted by at least oneheteroatom, optionally bearing at least one functional group and having6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having a total of 5 to 18 carbon atomsand/or heteroatoms, R¹², R¹³ are each independently, when A is N, a freeelectron pair, or, when A is C, hydrogen, linear or branched alkylradical optionally interrupted by at least one heteroatom, optionallybearing at least one functional group and having 1 to 20 carton atoms,cycloalkyl radical optionally interrupted by at least one heteroatom,optionally bearing at least one functional group and having 3 to 20carbon atoms, cycloheteroalkyl radical optionally interrupted by atleast one heteroatom, optionally bearing at least one functional groupand having 3 to 20 carbon atoms, substituted or unsubstituted arylradical optionally interrupted by at least one heteroatom, optionallybearing at least one functional group and having 6 to 30 carbon atoms,substituted or unsubstituted heteroaryl radical optionally interruptedby at least one heteroatom, optionally bearing at least one functionalgroup and having a total of 5 to 18 carbon atoms and/or heteroatoms,group with donor or acceptor action, R¹⁴, R¹⁵, R¹⁶, R¹⁷ are eachindependently hydrogen, linear or branched alkyl radical optionallyinterrupted by at least one heteroatom, optionally bearing at least onefunctional group and having 1 to 20 carbon atoms, cycloalkyl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having 3 to 20 carbon atoms,cycloheteroalkyl radical optionally interrupted by at least oneheteroatom, optionally bearing at least one functional group and having3 to 20 carbon atoms, substituted or unsubstituted aryl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having 6 to 30 carbon atoms, substitutedor unsubstituted heteroaryl radical optionally interrupted by at leastone heteroatom, optionally bearing at least one functional group andhaving a total of 5 to 18 carton atoms and/or heteroatoms, group withdonor or acceptor action, or R¹² and R¹³, R¹⁴ and R¹⁵, R¹⁵ and R¹⁶ orR¹⁶ and R¹⁷ form, together with A or the carbon atoms to which they arebonded, an unsaturated or aromatic, optionally substituted ringoptionally interrupted by at least one heteroatom and having a total of5 to 18 carbon atoms and/or heteroatoms, and/or if A⁶ is C, R¹³ and R¹⁴together form a saturated or unsaturated, linear or branched bridgeoptionally comprising heteroatoms, aromatic units, heteroaromatic unitsand/or functional groups and having a total of 1 to 30 carbon atomsand/or heteroatoms, to which is optionally fused a substituted orunsubstituted, five- to eight-membered ring comprising carbon atomsand/or heteroatoms.
 5. The metal-carbene complex of claim 1, wherein Lin the general formula (I) is a heterocyclic noncarbene ligand of thegeneral formula (III):

wherein: D are each independently CR¹⁸ or N; W is C, N; E are eachindependently CR¹⁹, N, or NR²⁰; G is CR²¹, N, NR²², S, or O; R¹⁸, R¹⁹,R²¹ are each independently hydrogen, linear or branched alkyl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having 1 to 20 carbon atoms, cycloalkylradical optionally interrupted by at least one heteroatom, optionallybearing at least one functional group and having 3 to 20 carbon atoms,cycloheteroalkyl radical optionally interrupted by at least oneheteroatom, optionally bearing at least one functional group and having3 to 20 carbon atoms, substituted or unsubstituted aryl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having 6 to 30 carbon atoms, substitutedor unsubstituted heteroaryl radical optionally interrupted by at leastone heteroatom, optionally bearing at least one functional group andhaving a total of 5 to 18 carbon atoms and/or heteroatoms, group withdonor or acceptor action, or in each case 2 R¹⁸, R¹⁹ and R²¹ radicals,together with the carbon atoms to which they are bonded, form asaturated, unsaturated or aromatic, optionally substituted ringoptionally interrupted by at least one heteroatom and having a total of5 to 18 carbon atoms and/or heteroatoms; R²⁰, R²² are each independentlya linear or branched alkyl radical optionally interrupted by at leastone heteroatom, optionally bearing at least one functional group andhaving 1 to 20 carbon atoms, cycloalkyl radical optionally interruptedby at least one heteroatom, optionally bearing at least one functionalgroup and having 3 to 20 carbon atoms, cycloheteroalkyl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having 3 to 20 carbon atoms, substitutedor unsubstituted aryl radical optionally interrupted by at least oneheteroatom, optionally bearing at least one functional group and having6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having a total of 5 to 18 carbon atomsand/or heteroatoms, group with donor or acceptor action; the solidcurved line is an optional bridge between one of the D groups and the Ggroup, and the optional bridge is selected from the group consisting ofalkylene, arylene, heteroarylene, alkynylene, alkenylene, NR²³, O, S,SiR²⁴R²⁵ and (CR²⁵R²⁷)_(d), where one or more nonadjacent (CR²⁶R²⁷)groups may be replaced by NR²³, O, SiR²⁴R²⁵, where d is 2 to 10; andR²⁴, R²⁵, R²⁶, R²⁷ independently represent H, alkyl, aryl, heteroaryl,alkenyl, or alkynyl.
 6. A process for preparing the metal-carbene ofclaim 1, the process comprising contacting at least one compoundcomprising M with at least one ligand or ligand precursor.
 7. Theprocess according to claim 6, comprising contacting the at least onecompound with at least one ligand precursor, wherein the ligandprecursor is a Ag-carbene complex.
 8. The process according to claim 6,comprising contacting the at least one compound with at least one ligandprecursor, wherein the ligand precursor is a compound of the generalformula (IV):

wherein Y is NR¹, O, S or C(R¹⁰)₂, A², A³, A⁴, A⁵ are each independentlyN or C, where 2 A=nitrogen atoms and at least one carbon atom is presentbetween two nitrogen atoms in the ring, R², R³, R⁴, R⁵ are each, if A²,A³, A⁴ and/or A⁵ is N, a free electron pair, or, if A², A³, A⁴ and/or A⁵is C, each independently hydrogen, linear or branched alkyl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having 1 to 20 carbon atoms, cycloalkylradical optionally interrupted by at least one heteroatom, optionallybearing at least one functional group and having 3 to 20 carbon atoms,substituted or unsubstituted aryl radical optionally interrupted by atleast one heteroatom, optionally bearing at least one functional groupand having 6 to 30 carbon atoms, substituted or unsubstituted heteroarylradical optionally interrupted by at least one heteroatom, optionallybearing at least one functional group and having a total of 5 to 18carbon atoms and/or heteroatoms, group with donor or acceptor action, orR³ and R⁴ together with A³ and A⁴ form an optionally substituted,unsaturated ring optionally interrupted by at least one furtherheteroatom and having a total of 5 to 18 carbon atoms and/orheteroatoms, R⁶, R⁷, R⁸, R⁹ are each independently hydrogen, linear orbranched alkyl radical optionally interrupted by at least oneheteroatom, optionally bearing at least one functional group and having1 to 20 carbon atoms, cycloalkyl radical optionally interrupted by atleast one heteroatom, optionally bearing at least one functional groupand having 3 to 20 carbon atoms, cycloheteroalkyl radical optionallyinterrupted by at least one heteroatom, optionally bearing at least onefunctional group and having 3 to 20 carbon atoms, substituted orunsubstituted aryl radical optionally interrupted by at least oneheteroatom, optionally bearing at least one functional group and having6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radicaloptionally interrupted by at least one heteroatom, optionally bearing atleast one functional group and having a total of 5 to 18 carbon atomsand/or heteroatoms, with a base skeleton selected from the groupconsisting of pyridyl, pyrimidyl, pyrazyl, triazolyl, pyrrole, furan,thiophene, pyrazole, triazole, oxazole and thiazole, group with donor oracceptor action, selected from the group consisting of a halogenradical, a silyl radical, a siloxy radical, an alkoxy radical, anaryloxy radical, a carbonyl radical, an ester radical, CH₂F, CHF₇ CF₃,CN, a thio group and SCN, or R⁶ and R⁷, R⁷ and R⁸ or R⁸ and R⁹, togetherwith the carbon atoms to which they are bonded, form a saturated,unsaturated or aromatic, optionally substituted ring optionallyinterrupted by at least one heteroatom and having a total of 5 to 18carbon atoms and/or heteroatoms, and/or if A⁵ is C, R⁵ and R⁶ togetherform a saturated or unsaturated, linear or branched bridge optionallycomprising heteroatoms, an aromatic unit, heteroaromatic unit and/orfunctional groups and having a total of 1 to 30 carbon atoms and/orheteroatoms, to which is optionally fused a substituted orunsubstituted, five- to eight-membered ring comprising carbon atomsand/or heteroatoms, R²⁸ is independently SiR²⁹R³⁰R³¹, aryl, heteroaryl,alkyl, cycloalkyl or heterocycloalkyl, and R²⁹, R³⁰, R³¹ are eachindependently aryl, heteroaryl, alkyl, cycloalkyl or heterocycloalkyl.9. An organic electronic component, comprising at least onemetal-carbene complex of claim
 1. 10. The organic electronic componentaccording to claim 9, which is an organic light-emitting diode (OLED),organic photovoltaic cell (OPV), organic field-effect transistor (OFET)or light-emitting electrochemical cell (LEEC).
 11. A light-emittinglayer, comprising at least one metal-carbene complex according toclaim
 1. 12. An OLED, comprising a light-emitting layer according toclaim
 11. 13. An OLED., comprising at least one metal-carbene complexaccording to claim 1, and at least one compound of the formula (X):

wherein: T is NR⁵⁷, S, O or PR⁵⁷; R⁵⁷ is aryl, heteroaryl, alkyl,cycloalkyl or heterocycloalkyl; Q′ is —NR⁵⁸R⁵⁹, —P(O)R⁶⁰R⁶¹, —PR⁶²R⁶³,—S(O)₂R⁶⁴, —S(O)R⁶⁵, —SR⁶⁶ or —OR⁶⁷, preferably —NR⁵⁸R⁵⁹; R⁵⁵, R⁵⁶ areeach independently alkyl, cycloalkyl, heterocycloalkyl, aryl,heteroaryl, SiR⁷⁰R⁷¹R⁷², a Q′ group or a group with donor or acceptoraction; a″ is 0, 1, 2, 3 or 4; b′ is 0, 1, 2 or 3; R⁵⁸, R⁵⁹ form,together with the nitrogen atom, a cyclic radical which has 3 to 10 ringatoms and may be unsubstituted or substituted by one or moresubstituents selected from the group consisting of alkyl, cycloalkyl,heterocycloalkyl, aryl, heteroaryl and a group with donor or acceptoraction, and/or may be fused to one or more further cyclic radicalshaving 3 to 10 ring atoms, where the fused radicals may be unsubstitutedor substituted by one or more substituents selected from the groupconsisting of alkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl anda group with donor or acceptor action; R⁷⁰, R⁷¹, R⁷², R⁶⁰, R⁶¹, R⁶²,R⁶³, R⁶⁴, R⁶⁵, R⁶⁶, R⁶⁷ are each independently aryl, heteroaryl, alkyl,cycloalkyl or heterocycloalkyl, or two units of the general formula (X)are bridged to one another through a linear or branched, saturated orunsaturated bridge optionally interrupted by at least one heteroatom,through a bond or through O.
 14. The OLED according to claim 13,comprising at least one compound of the formula (XI) or (XI*):

wherein: T is NR⁵⁷, S, O or PR⁵⁷; R⁵⁷ is aryl, heteroaryl, alkyl,cycloalkyl or heterocycloalkyl; Q′ is —NR⁵⁸R⁵⁹, —P(O)R⁶⁰R⁶¹, —PR⁶²R⁶³,—S(O)₂R⁶⁴, —S(O)R⁶⁵, —SRS⁶⁶ or —OR⁶⁷; R⁷⁰, R⁷¹, R⁷² are eachindependently aryl, heteroaryl, alkyl, cycloalkyl, heterocycloalkyl,where at least one of the R⁷⁰, R⁷¹, R⁷² radicals comprises at least twocarbon atoms, or OR⁷³, R⁵⁵, R⁵⁶ are each independently alkyl,cycloalkyl, heterocycloalkyl, aryl, heteroaryl, a Q′ group or a groupwith donor or acceptor action; a′, b′ for the compound of the formula(XI): are each independently 0, 1, 2, 3; for the compound of the formula(XI*), a′ is 0, 1, 2 and b′ is 0, 1, 2, 3, 4; R⁵⁸, R⁵⁹ form, togetherwith the nitrogen atom, a cyclic radical which has 3 to 10 ring atomsand may be unsubstituted or substituted by one or more substituentsselected from the group consisting of alkyl, cycloalkyl,heterocycloalkyl, aryl, heteroaryl and a group with donor or acceptoraction and/or may be fused to one or more further cyclic radicals having3 to 10 ring atoms, where the fused radicals may be unsubstituted orsubstituted by one or more substituents selected from the groupconsisting of alkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl anda group with donor or acceptor action; R⁷³ are each independentlySiR⁷⁴R⁷⁵R⁷⁶, aryl, heteroaryl, alkyl, cycloalkyl or heterocycloalkyl,optionally substituted by an OR⁷⁷ group, R⁷⁷ are each independentlySiR⁷⁴R⁷⁵R⁷⁸, aryl, heteroaryl, alkyl, cycloalkyl or heterocycloalkyl,R⁶⁰, R⁶¹, R⁶², R⁶³, R⁶⁴, R⁶⁵, R⁶⁶, R⁶⁷, R⁷⁴, R⁷⁵, R⁷⁶ are eachindependently aryl, heteroaryl, alkyl, cycloalkyl or heterocycloalkyl,or two units of the general formulae (XI) and/or (XI*) are bridged toone another through a linear or branched, saturated or unsaturatedbridge optionally interrupted by at least one heteroatom or through 0,where this bridge in the general formulae (XI) and/or (XI*) is in eachcase attached to the silicon atoms in place of R⁷¹.
 15. The OLEDaccording to claim 14, wherein R⁷⁰ and/or R⁷¹ and/or R⁷² in thecompounds of the general formula (XI) or (XI*) are aromatic units of thegeneral formulae (XIi) and/or (XIi*):

wherein: T is NR⁵⁷, S, O or PR⁵⁷; Q′ is —NR⁵⁸R⁵⁹, —P(O)R⁶⁰R⁶¹, —PR⁶²R⁶³,—S(O)₂R⁶⁴, —S(O)R⁶⁵, —SRS⁶⁶ or —OR⁶⁷; R⁵⁵R⁵⁶ are each independentlyalkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, a Q′ group or agroup with donor or acceptor action; and a′, b′ for the compound of theformula (XIi): are each independently 0, 1, 2, 3; for the compound ofthe formula (XIi*), a′ is 0, 1, 2 and b′ is 0, 1, 2, 3,
 4. 16. The OLEDaccording to claim 13, comprising an emission layer comprising the atleast one metal-carbene complex, and at least one matrix material. 17.The OLED according to claim 12, comprising an electron-transportinglayer comprising at least two different materials, of which at least onematerial is electron-conducting.
 18. The OLED according to claim 17,wherein the electron-transporting layer comprises at least onephenanthroline derivative and/or pyridine derivative.
 19. The OLEDaccording to claim 17, wherein the electron-transporting layer comprisesat least one phenanthroline derivative and/or pyridine derivative and atleast one alkali metal hydroxyquinolate complex.
 20. The OLED accordingto claim 17, wherein the electron-transporting layer comprises at leastone phenanthroline derivative and/or pyridine derivative and8-hydroxyquinolatolithium.
 21. A device, comprising at least one OLEDaccording to claim 12, wherein the device is at least one selected fromthe group consisting of a stationary visual display unit, a mobilevisual display unit and an illumination unit.
 22. An OLED, comprisingthe metal-carbene complex according to claim
 1. 23. The OLED accordingto claim 22, wherein the metal-carbene complex is at least one selectedfrom the group consisting of an emitter, a matrix material, a chargetransport material and a charge blocker.